# Lighting Spectrum



## fishfan

Hello I have a basic question about fluorescent bulb color in relation to plant growing. Since starting with plants I have tried three different 'colors' of fluorescent light bulb, a whitish tinted one, a yellowish one, and a pinkish glowing bulb which enhances fish colors. 
I am wondering if one type of bulb produces a better light for plant growing? I have heard that some recommend a whiter glowing bulb as it produces a more natural light that plants can use in photosynthesis. Or does the color not even matter but just the wattage? Thanks.


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## phanmc

The wattage and type of bulb (NO fl, T5HO, CF, MH) is more important than the color temp. In general, bulb types of the same kind perform about the same (5000k CF are about equal to 6700k CF). There may be some minor differences but you'll be hard pressed to notice them, and the differences are likely more related on what phosphors the manufacturers used to achieve the color.

When buying lights, the most important things are whether or not you like the color and whether they are a good bargain.


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## DonaldmBoyer

I'm sorry to disagree with phanmc (unless I misunderstood what he was trying to say), but the most important thing to consider when buying fluorescent bulbs is not only HO, VHO, etc., but also the K, and phanmc alluded to. If you want to grow plants well, it depends also on the size of your aquarium. If it is smaller, you can use NO (normal output) T5's or a cheap fluorescent tube; if it is bigger, you will need VHO T5's, T8's, or power compact fluorescent lighting, and probably a bunch of them! Plants grow well in K ratings between 6700K-10000K; I have found that a combination of bulbs between that K range not only produces the best plant growth, but is also more "natural" looking. Not too yellow, not too blue either.

For instance, on my 100 gallon tank, I have ten 65 watt power compact fluorescent bulbs; six are 10000K, two are 6700K, and two are 8600K. That puts me around 7 watts per gallon worth of lighting, once you compensate for water displacement for the substrate and hardscape. Also, this combination of K's gives me a more "natural" look for the lighting.

To a degree, this can also vary as some people prefer 6700K, some 10000K, and some like combinations of these bulbs or bulbs that are in between this range. Some metal halide lighting goes up to at least 12000K; other bulbs also go below 6700K as well. From my experience, I prefer the look and get the best plant growth with bulbs that lie with the K range of 6700K and 10000K's. I think that perhaps phanmc may have insinuated this (?) already.


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## phanmc

You didn't misunderstand me, I'm saying the K rating is a very inaccurate measurement for the sake of plant growth and that it is only useful in determining color preference.

Take a look at this old bulb comparison page:

http://www.aquabotanic.com/lightcompare.htm

Some of the things to take away are:

You can have two bulbs with the same k rating but their efficiency in PAR would be different. The Philips Advantage fluorescent 5000K is the most efficient bulb on the chart (better than even the 6500k metal halides) while the Philips TL950 5000K is one of the worst FL.

Lumens can have a very large range of difference but the PAR efficiency difference are much smaller.

Cool whites (4000k) aren't too shabby at growing plants, of course most don't like the yellow tint.

Now what color temp YOU prefer is important. If you find that the 6700k is still too yellow for you then by all means use the 10000k or higher bulbs. If you find the 6700k too white, try out the 5000k bulbs.


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## Left C

Most aquarium plant lamps serve two purposes:
1) grow plants
2) make the aquarium pleasing to the eye

A lamp made specifically for growing plants probably wouldn't be very pleasing to the eye. Many times there are a green and yellow spike added in the color spectrum of the lamp to make the aquarium look better.

Here's an example. The red looking lamp is for growing plants only. It's made by SolarOasis.
http://www.plantedtank.net/forums/lighting/26464-seans-led-growlights.html


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## Squawkbert

The best planted tank bulbs are the ones that provide a good amount of light at the plant-critical wavelengths (higher UV/lower vis range 400-700nm) and are pleasing to the human eye. 
6500K-6700K bulbs tend to provide a decent amount of light in this range while having a decent CRI (color rendering index - ie: how much it looks like sunlight) - somewhere in the 90s. The human eye generally prefers a higher CRI. Low K lamps are frequently pink in appearance, very high K lamps (10K-14K) are usually blue. Both tend to have CRIs in the 20-40 range.
GE makes a 9300ish K bulb that seems to be popular with planted tank folks. I haven't seen one yet, but to have that high a K rating and a decent CRI, they must be doing a good job of hiding a pretty good 300-400nm spike in the output spectrum.


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## DonaldmBoyer

Phanmc--

I thought that I probably misread your first post....sorry! 

My only point is that one needs something fairly bright and powerful (in terms of watts) in order to grow plants well. The color of the bulb is subjective, but ONLY to a degree. Obviously, something with a green wavelength would be awful because most plants don't use green wavelengths of light for photosynthesis (which is why they are green....they reflect green light). You ideally need something that emits not only red wavelengths, but also blue as those wavelengths are needed by plants for photosythesis, but are largely absorbed by the water and don't penetrate very far into the aquarium.

That's all!!


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## ruki

Lighting always gets rather complicated. Color does matter, but the human eye isn't very good at determining if the colors needed for plant growth are strongly represented in the tube.

Kelvins for a bulb is usually a bit more accurate a description than "watts per gallon"  But both measures are an approximation/estimate and are not to be taken as a firm rule, but are better than nothing so we keep using them. The color spectrum chart for a bulb is much better to use. It's pretty easy to determine from the chart that there are red and blue peaks in the spectrum useful for plants.

*A note on CRI*
This is something for interior designers. It reflects a human eye balance with red, green and blue so colored objects look the same outside in sunlight as they do inside under artificial light. However, a high CRI number indicates a balance between blues and reds which usually means better light for plants when comparing tubes designed to illuminate human work areas.

*A note on PAR*
There limitations to PAR.
* Measuring equipment is really expensive, so it's not practical to measure it.
* Most tubes don't include this info. Lumens are used instead which includes light outside of the PAR range.
* More serious is that PAR includes greens. Green isn't used by photosynthesis, so even the PAR number isn't an absolute either.

*Cool white*
Earlier cool white tubes included a small far blue spike in the spectrum which was useful to plants that didn't need high light. These were labeled cool since they looked blue when compared against the warm white ~3000K tubes. Today's tri-phosphor tubes have a more balanced spectrum and what used to be labeled as cool white is now labeled as 4100K. High CRI versions (i.e. T8 Octron) have enough blue to do a decent job at growing plants.

*Two tube approach*
What works well for me is to use two tubes. One tube for reds and one tube for blues. This is frequently cheaper, since it's more expensive to get a custom tube that produces both.

*The red tube*
After looking at many tube spectrum charts, I noticed that most tubes do not produce very strong reds. Marketing for plant tubes can be misleading  Two of the best red produces are GroLux and ZooMed plant bulbs. Any others out there? These were the best that I could find, so I use them. This is the tube that looks really strange from the human eye perspective, so as a previous posted mentioned you will want to use another tube to make the aquarium more pleasing to the human eye.

*The blue tube*
The blue tube isn't as critical, many tubes produce decent blues. In general, a 6500K or higher number tube produces good blues. This is since the Kelvins number for fluorescent tubes is something of an average, and you need good blue contribution to the overall average to increase it. So, sometimes you can make some decent conclusions based upon a number that represents an estimate 

So the answer is to look up the color chart for your bulbs and see how they do in producing reds and blues. Many combinations of tubes will do a decent job.

Then you want to get this light into the aquarium and to the plants. So a good reflector helps out (linear tubes work better then bent tubes with reflectors) and not too deep of a tank helps since water, and especially stuff suspended in it, absorbs significant light as well. However, reds are absorbed more than blues if your water is clear.


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## Newt

Ruki, You are correct about the red region of the spectrum where it is not high enough in the nanometer range to properly aid in plant growth. The most appropriate range is 660nm and most bulbs dont get above 625nm except for the GroLux, ZooMed and the Aqua-glo. This is because the red phosphourus is very expensive. Sylvania doesn't give a kelvin rating for the GroLux bulb but the Aqua-glo (a lower powered version of a GroLux) is given a kelvin rating of 18,000K so I am going to guess the GroLux would be higher than that and be around 22,000K +/-.

I have never seen a CF bulb with anything higher than 625nm and not very high in strength or at least compared to the GroLux.

The kelvin rating of a bulb has absolutely nothing to do with how it will affect plant growth. It is merely how it will make your tank appear to you, the human viewer. The human eye is 'geared' toward the green area of the spectrum (brightness) which does nothing for plants. Plants react to blue and red light for photosynthesis and these colors are available in varying amounts in about all fluorescent lights. So a bulb with a kelvin rating of 4000K will have blue and red but be weighted more toward the red and a bulb rated at 7500K will be weighted more toward the blue end of the visible spectrum. You need a bulb with more red than blue as the red is absorb by the depth of water more than blue. ie. blue light penetrates deeper than red.

http://www.aquaticplantcentral.com/...lighting/38014-lighting-planted-aquarium.html


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## Left C

Newt, that's an excellent article that you wrote about light. I enjoyed the whole thread.

Here's a very good summary article about photosynthesis. It has information about light and how plants use it for photosysthesis. There's information about the Dark Reaction too. I hope that it will help you, fishfan. http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html


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## ruki

Newt said:


> Sylvania doesn't give a kelvin rating for the GroLux bulb but the Aqua-glo (a lower powered version of a GroLux) is given a kelvin rating of 18,000K so I am going to guess the GroLux would be higher than that and be around 22,000K +/-.


To me, it doesn't make much sense to give a plant bulb a Kelvins number. In a way, the bulbs for human eyes are trying to simulate (via red, blue, green) a hot object in a vacuum. So you can give it a K number since to human eyes it's like being on a planet around a star of that temperature. A black-body curve is continuous, so it's a bit of a reach to give any fluorescent tube a Kelvins number. A plant bulb isn't trying simulate a continuous curve at all, so a K number seems not appropriate. A plant bulb is something like being in orbit around a binary system with an old red star and young blue star. :lol:



> The kelvin rating of a bulb has absolutely nothing to do with how it will affect plant growth. It is merely how it will make your tank appear to you, the human viewer. The human eye is 'geared' toward the green area of the spectrum (brightness) which does nothing for plants. Plants react to blue and red light for photosynthesis and these colors are available in varying amounts in about all fluorescent lights. So a bulb with a kelvin rating of 4000K will have blue and red but be weighted more toward the red and a bulb rated at 7500K will be weighted more toward the blue end of the visible spectrum. You need a bulb with more red than blue as the red is absorb by the depth of water more than blue. ie. blue light penetrates deeper than red.


So what you are saying seems to be: For fluorescent tubes, how much red is what is most important. But, I don't think that's the whole story. Let's refer to page 180 of walstad's book notes the following on oxygen production for fluorescent tubes. Different tubes do produce different growth rates:

47 = CW + VL
37 = CW + CW
25 = VL + VL
23 = CW + WW
21 = DL + DL

CW =~ 4100K bulb
VL =~ VitaLight plant bulb
DL =~ 5000K bulb
WW = 3500K bulb

These are hard numbers, which are opposite of what I earlier recommended. With good reds, I thought it was important to emphasize blues for balance. It does work out that way for aesthetics, but for plant growth the more output efficient 4100K bulb did better when combined with a plant bulb. 4100K bulbs are quite efficient, so they produce superior results when paired up with a plant bulb. As a bonus, these are the cheapest type of fluorescent tube to obtain 

Any hard numbers that say other than cool white plus plant bulb produces the most growth?


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## Newt

Thank you, Left C.

Very interesting article. I have a srap book I keep of aquarium facts and a large section on lighting and bulb data. I thought this was an article I had but it turns out it just uses a number of the same graphs and such. I will add this to my reference data. I keep an electronic version and a hard copy.

Ruki, you lost me on the right turn after Saturn. LOL. I dont get overly enthused over Diana Walstad she seems to ignore scientific data and soley rely on home experimentation. After all, shes just like all of us here>>>>>an aquarium keeper; but she wrote a book.

Based on the info you provided it would seem that the best combo has the most red light. I believe the Vitalite is a full spectrum bulb and not a true plant bulb, but I'm not certain. The Cool White bulbs have a good amount of blue and red. The europeans tend more towards the 4100K bulbs and IMO they have the best looking tanks. Maybe we should copy them.

The Hagen Aqua-glo is a plant bulb and it does fall around the 18000K range (lavender) and if you follow the black body locus line it turns from lavender to purple (violet) which is about where the GroLux light appears.


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## Left C

You are very welcome, newt.


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## ruki

Don't want to cause too much trouble, but love to ask questions. Really wish we had better access to something with numeric measurements that we could confirm the theory with. Think Diane's book is really nice. We could use a dozen more like these to get a better picture from multiple perspectives.


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## fishstein

I agree that the best method to achieve visually pleasing light is to mix bulbs, particularly low K of around 5000-6500K with higher K (in my case 10,000K) - I get great rendition of greens, reds and all colors.

Photosynthetic efficiency really matters. Case in point. I was using 4 Verilux 6500K 94.5 CRI bulbs. I got good growth. I then read about the Phillips ADV850 5000K Advantage bulb and the Phillips TLD89 Aquarelle 10000K bulb and so photos of these bulbs combined online. Very pleasing visible light. But better yet - my plant growth significantly improved with the same wattage. In fact, I was so surprised I went and put new Verilux 6500K 94.5 CRI bulbs back in to see if the issue was just old T8 bulbs - it wasn't. The ADV850 is a fantastically efficient bulb for plant growth and has excellent red light for plants. The Aquarelle is also excellent for plant growth. Note that I am not a retailer or importer of these bulbs.

I wish I could find these bulbs in T5. The most efficient T8 bulbs I've ever seen for combination of excellent plant growth (both vertical and lateral - yes, different types of light will get you different growth) and wonderfully pleasing full spectrum light highlighting a wide range of colors. Makes your aquarium plants and fish really pop.


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## Newt

Agreed; especially when you use a plant bulb, the mixing of lighting works out best.

The Verilux isnt a good plant bulb at all as you can see by the graph below:









Philips Aquarelle (10,000K)









Philips ADV850 et al:


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## fishstein

Know of T5 bulbs with the properties of the T8 Phillips Aquarelle TLD89 10000K or the Phillips ADV850 5000K? Or one T5 bulb which combines the properties of both?

No T5 bulb I've looked at comes close these two fantastic T8 bulbs I use now.


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## Newt

The Philips PLL950; 5000K; 92 CRI:









A 5300K version (European) was available thru www.aamsco.com with a call to Liz Congerio at the Florida tele number.

The PLL950 is the best I have been able to find in T5 CF for planted tanks. It is a nice white light. Philips also makes a few others with a lower kelvin rating that are popular in Denmark and Poland areas of Europe.

CF technology for spectral output for planted tanks isn't there yet. The red phosphour is VERY expensive so you can't find bulbs with red output around 660nm.

Those Geisemann bulbs look great but I'd have to get a TEK linear fixture. Still the CFs are more effiecient.

Also try www.ahsupply.com and look for the 5500K with 92 CRI. They just dont have a spectral graph available.


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## Newt

Almost forgot these Sylvania bulbs a friend on the west coast told me about:


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## fishstein

Thanks Newt - are any of these bulbs available for T5 (not CF)? T5 is better for lighting 4 ft tanks.


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## Newt

I'm not aware of any of those available in linear T5. Perhaps the Pentron from the normalized spectral graph with the 6 different bulbs.

Why do you say the linear T5's are better than the T5 CFs at lighting 4 ft. tanks???


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## defdac

ruki said:


> * Most tubes don't include this info. Lumens are used instead which includes light outside of the PAR range.


Lumens is inside the PAR-range. It's the yellow-green light, and as you noted yellow-green is reflected by plants.

This means a green lamp have high lumens and PAR, but low PUR.

A blue+red lamp without yellow-green light have low lumens and high PAR, and high PUR.

Confusing, I know.

With the CIE's 1988 photooptic curve, the lumensrating of the bulb, the wattage and the spectral distribution one can calculate how much PUR a bulb is emitting. Read more about it here:
http://www.aquabotanic.com/lightcompare.htm


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## fishstein

Hi Defdac,

I used that site and the photos you posted of various bulbs to choose my bulbs - I used the exact same T8 Phillips Aquarelle and ADV850 bulbs you use. They are fantastic. Thanks for posting your comments and photos of them.


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## defdac

Yepp they manage to produce some serious pearling och growth and the funny thing is that they have the highest PUR-efficiency of almost all bulbs if you start to count on it like in the Ivo Busko article http://www.aquabotanic.com/lightcompare.htm

So advanced theory goes hand in hand with the real world. To me that is amazing, you can actually put the universty math to something useful =)


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## ruki

defdac said:


> Lumens is inside the PAR-range. It's the yellow-green light, and as you noted yellow-green is reflected by plants.
> 
> This means a green lamp have high lumens and PAR, but low PUR.
> 
> A blue+red lamp without yellow-green light have low lumens and high PAR, and high PUR.
> 
> Confusing, I know.
> 
> With the CIE's 1988 photooptic curve, the lumensrating of the bulb, the wattage and the spectral distribution one can calculate how much PUR a bulb is emitting. Read more about it here:
> http://www.aquabotanic.com/lightcompare.htm


PUR makes alot of sense. 'Photosynthetic Usable Radiation', the light that actually gets used for photosynthesis. I wonder how this was calculated...


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## fishstein

So anyone know where to find a high PAR and high PUR T5 4ft bulb that throws nice visible light which highlights red and green colors in the tank, like my Phillips Aquarelle 10000K TLD89 + my Phillips Advantage ADV850 T8 bulbs? I still haven't found any T5 bulbs that come close to the combination of pleasing visible light and high photosynthetic efficiency.


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## Left C

ruki said:


> PUR makes alot of sense. 'Photosynthetic Usable Radiation', the light that actually gets used for photosynthesis. I wonder how this was calculated...


Hi Ruki

Check out the *Steps to compute the tabulated quantities:* in the Ivo Busko article that defdac posted.

I don't believe that I want to tackle it.


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## defdac

You can use my calculator also, it's still in beta I'm afraid - next version will have better layout and frequency based attenuation (which will penalize reds quite a bit): http://82.183.138.227/GTKTest/GTKTest.html
Also, I need to get hold of a lux-meter and a couple of different reflectors to be able to give guidelines to the reflector efficiency.


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## gf225

ruki said:


> *The red tube*
> Two of the best red produces are GroLux and ZooMed plant bulbs. Any others out there?


Dennerle Special-Plant (3000K)
Hagen Flora-Glo (2800K)
Arcadia Original Tropical (?K)


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## fishstein

Hi George, are those bulbs T5, T8 or CF?

Can anyone recommend a combination of T5 bulbs that will produce good PAR and PUR and throw a mix of visible light that will highlight both red and green plants? See the PAR and PUR of the T8 bulbs I'm using in the article to get a sense of what I'm looking for in T5: Phillips Aquarelle TLD89 10000K and Phillips Advantage ADV850 5000K.

Aaron, I saw the photo you posted of your tank under the Geissmann T5 6000K bulb - overall not bad, but the few reds appeared washed out. Ideally to see the how the Geissmann 6000K bulbs light a tank, you'd have to photograph the tank under them and under other bulbs keeping the same settings on the camera.


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## Newt

The Flora_glo really doesnt have much red light:









The Aqua-Glo is their plant bulb:








But this just an underpowered GroLux and at the price of the Hagen bulbs you are better off with the GroLux.

I dont have graphs for the other two (yet).

Fishstein: your best bet is the combo of the Giesemann Midday and Aquaflora bulbs.


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## fishstein

Thanks Newt,

Do you know if the Sylvania Grolux bulb is available in a T5 4ft bulb?

If it is, why not combine the Sylvania Grolux with the Giesemann Midday bulb?


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## Newt

Sylvania only makes the 48" GroLux Standard and Wide Spectrum bulbs in a medium bi-pin T12 size.
I had correspondence with Sylvania in 2003 and at that time they had no plans to make the GroLux in a T5 linear or CF.


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## gf225

Hi Newt,

I think the graph you have for the Aqua Glo is in fact for the Flora Glo.



fishstein said:


> Hi George, are those bulbs T5, T8 or CF?


T8, and I think the Arcadia and Dennerle rare in the US.

For T5 with both good colour rendition (greens) and plant growth (reds, blues) I recommend a mix of Giesemann Midday 6000K and Aqua Flora, 3:1 or 2:2.


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## defdac

Newt, I had the GroLux in T8, and here are the T5:s:
http://www.aquaristikshop.com/cgi-b...c=568060&t=pangora&zusatz=1&p=preisroboter.de


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## Newt

defdac said:


> Newt, I had the GroLux in T8, and here are the T5:s:
> http://www.aquaristikshop.com/cgi-b...c=568060&t=pangora&zusatz=1&p=preisroboter.de


Cool

Are they available in the States? I went to the Sylvania website and couldn't find them.

Thank you.


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## Newt

gf225 said:


> Hi Newt,
> 
> I think the graph you have for the Aqua Glo is in fact for the Flora Glo.
> QUOTE]
> 
> Nope, it is the aqua-glo;
> 
> Here is a link to their site for the aqua-glo.
> 
> http://www.hagen.com/usa/aquatic/product.cfm?CAT=1&SUBCAT=112&PROD_ID=01015870020101


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## ruki

One caution is that the spectral charts might not be as accurate as we would want. Can we can always trust the vendors? The seminal Aquatic Botanic bulb comparison article http://www.aquabotanic.com/lightcompare.htm had a paragraph on this.


> The main results are presented in the tables that follow. The Hagen bulbs have published spectra which clearly show systematic distortion in the emission profiles not caused by the spectrophotometer characteristics, but more likely by doctoring at the marketing department. Such data cannot be compared with other bulbs unless very approximately, so their data is reported in a separate table. Relative comparisons among the Hagen bulbs should still be possible though (with a grain of salt).


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## Newt

When in doubt, always blame the Marketing Dept.

I'm glad you pointed thgis out, Ruki.

The same goes for labeling any bulb with a specific kelvin rating.

If your product doesnt meet the goals of the hobbists>>>>LIE!


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## fishstein

Anyone know if the T5 GroLux is available in the U.S.?

Also, what color visible light does it throw? A sort of dim purple/red which makes everything look purple/pink/reddish? That's OK by me as long as I combine it with the Midday and Aquaflora.


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## Newt

Here is the visible spectrum (for humans):

















Here is the output within the visible spectrum for the GroLux:









The Philips 6500K Day Light bulb (available in T5 48' linear at Home Depot et al) will balance out the dim purplish color when mixed:


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## fishstein

Have you seen how the Philips 6500K Day Light T5 looks combined with the GroLux T5? Or have you seen how these same bulbs look mixed in T8 or T12? Hate to go just by manufacturer's claim. Some lights throw really different color than you'd expect.

How much do those Phillips 6500K T5 bulbs go for at Home Depot?

Thanks very much for pointing this out. I have great T8s, but was trying to find out what equivalent would be in T5 for another tank, and this forum has provided some great info. Now I only wish someone had photographed the same tank under these various bulbs...


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## Newt

I have used the 40 watt GroLux Std (48") T12 with the Philips F40DX 6500K T12 and it looks great combined. Here is a picture with them in use along with (2) Philips PLL950s 55 watt CFs (5000K).










The T12 cost about $7.00 for two. I forget the price of the linear Philips DayLight T5s as I have not purchased them.


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## Newt

defdac said:


> Newt, I had the GroLux in T8, and here are the T5:s:
> http://www.aquaristikshop.com/cgi-b...c=568060&t=pangora&zusatz=1&p=preisroboter.de


Defdac,

I looked into the link/site a bit more on the T5 GroLux and the spectral output they show is not the same as the 'old' standard GroLux, or at least from what I could tell.

I have emailed Sylvania to see if I can get some more info on this. I will let you all know what I find out.

You guys in Europe sure have a lot more and better accessories to choose from in the aquatic world. Lucky...............


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## defdac

ruki said:


> One caution is that the spectral charts might not be as accurate as we would want. Can we can always trust the vendors?


I got me a $25 Project STAR spectrometer and made a software that converts the spectrum to an ordinary spectral distribuation diagram like this:
http://www.defblog.se/picture/1691.html

It's not completely exact due to the IR-filter in the camera and the fact that the R, G and B-sensors doesn't overlap exactly, but I can check if they are good and within reason.

Big vendors like Philips, Osram etc have good spectral distributions and you can see when they are fairly "good" looking. Smaller vendors like Hagen have very fabricated spectral distributions nothing like you would get from a spectral measurement. Looks like something from a toy store:
http://aquagarden.iespana.es/fotos/aquaglo.gif


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## defdac

It seems that the lumens output is the value to really question since it's very hard to measure. You need a gigantic integration sphere to fit the bulbs in and then have calibrated equipment to get a good measure...


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## Newt

ruki said:


> One caution is that the spectral charts might not be as accurate as we would want. Can we can always trust the vendors? The seminal Aquatic Botanic bulb comparison article http://www.aquabotanic.com/lightcompare.htm had a paragraph on this.


No, we can't trust the marketing departments. Especially when they provide a spectral output in % relative intensity and not something meaning full such as watts/5 nm/1000 lumens.

Defdac seems to have lots of good info and being from europe will have much better equipment to talk about and a better understanding of planted aquaria and its needs.


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## ruki

defdac said:


> I got me a $25 Project STAR spectrometer and made a software that converts the spectrum to an ordinary spectral distribuation diagram like this:
> http://www.defblog.se/picture/1691.html
> 
> It's not completely exact due to the IR-filter in the camera and the fact that the R, G and B-sensors doesn't overlap exactly, but I can check if they are good and within reason.
> 
> Big vendors like Philips, Osram etc have good spectral distributions and you can see when they are fairly "good" looking. Smaller vendors like Hagen have very fabricated spectral distributions nothing like you would get from a spectral measurement. Looks like something from a toy store:
> http://aquagarden.iespana.es/fotos/aquaglo.gif


I have one of those spectrometers. Through the eye, it's very good for determining the presence of a particular wavelength, but of course not so great on measuring the intensity of the spikes. You process takes this to a whole other level. Really neat.

My first problem is taking decent photos. I used a 1:1 lens in my Digital Rebel, but getting the exposure correct is not easy for me.

It isn't obvious what you are doing once you have a properly exposed picture. Are you taking intensity levels via Photoshop and then feeding that to a plotting program?


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## ruki

defdac said:


> It seems that the lumens output is the value to really question since it's very hard to measure. You need a gigantic integration sphere to fit the bulbs in and then have calibrated equipment to get a good measure...


What might work for us as a rough estimate is putting a light meter on the bottom of an empty aquarium. You could at least compare fixtures with ~"standard"~ lights.

Doing it the absolutely correct way with scientific instruments is very expensive.


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## defdac

ruki said:


> My first problem is taking decent photos. I used a 1:1 lens in my Digital Rebel, but getting the exposure correct is not easy for me.


My Coolpix 4500 have a supermacro-mode making it fairly easy to take a good picture - but I would really like to modify the lens in my QuickCam3000 to be able to shoot good pictures from the project star spectrometer since I have removed the IR-filter from it. That would make the spectral distribution accurate over 650 nm.



> It isn't obvious what you are doing once you have a properly exposed picture. Are you taking intensity levels via Photoshop and then feeding that to a plotting program?


I cut out the 400-700 nm part of the spectrum-picture from the Project STAR, reverse it to make the blue part on the left, desaturates it, and then I scale it down to 1x400 pixels and makes an "auto levels".

Then I input this 1x400 pixel picture into a Java-program I've made which extracts the RGB-values and paints a B&W-distribution where black in the original picture is a bar with height 0 and white (255,255,255) is a bar with height 255.


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## ruki

Wow, that's quite clever!


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## rs79

For lower wattage (T12 4 foot) stuff I use wide spectrum gro lux mixed with 5000K or better cheap tubes I find in the hardware store.

Philips makes "agro lite", GE makes "plant and aquarium" and Osram Sylvania makes "Gro lux". They're basically the same thing.

GE makes the "Chroma 50" (Marked "C50" on the tube), Philips makes "Colortone 50" and I don't remember what Osrams 5K tube is. All these are available in bigger hardware stores.

When mixed they come out pretty decent.

My friends around here think I'm nuts and they use the venerable cool white/warm white mix used for 40+ years. Both work around the same frankly. I try to convince myself my exotic light gives better growth but I know I'm deluding myself.

Besides, I just like the way it looks.

For my 40W biax CFL's (I have way more of these) I just use warm white cause they're cheap. They work spectacularly well.


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## ruki

rs79 said:


> For lower wattage (T12 4 foot) stuff I use wide spectrum gro lux mixed with 5000K or better cheap tubes I find in the hardware store.
> 
> Philips makes "agro lite", GE makes "plant and aquarium" and Osram Sylvania makes "Gro lux". They're basically the same thing.
> 
> GE makes the "Chroma 50" (Marked "C50" on the tube), Philips makes "Colortone 50" and I don't remember what Osrams 5K tube is. All these are available in bigger hardware stores.
> 
> When mixed they come out pretty decent.


Mixing wide spectrum with another tube should work OK. But the plants don't need wide spectrum, just reds and blues, so I use the standard Gro-Lux or Zoomed plant tube. Lots of combos will produce good results though. I use Osram/Sylvania's 65000K octron since it's cheap, easy to find and very efficient.

Plant bulbs are not the same thing though. GroLux has considerable deep reds. Zoomed also has deep reds. The other plant bulbs really don't produce the deep reds. Reds get attenuated by water more than the blues, so in theory extra reds should help grow aquatic plants.



> My friends around here think I'm nuts and they use the venerable cool white/warm white mix used for 40+ years. Both work around the same frankly. I try to convince myself my exotic light gives better growth but I know I'm deluding myself.


Would most people even notice a doubling of plant growth if the tubes really did make that much of a difference? You might need two side-by-side tanks to see it. Some of the more difficult to grow plants might be easier to see a difference though.

Also, the phosphors have changed over the years and the warm white and cool white have much better CRI and efficiency than they had years back.

It's no delusion. Not all tubes are not the same. I think it was Fishstein who reported very noticeable results with a combination of Phillips tubes that did very well in the Aqua Botanic bulb comparison (http://www.aquabotanic.com/lightcompare.htm). In theory, this totally kick @ss over a cool white/warm white bulb comparison.

Of course this goes against the "good enough" with something easier to obtain.


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## gf225

ruki said:


> * More serious is that PAR includes greens. Green isn't used by photosynthesis, so even the PAR number isn't an absolute either.


Appararently some green is used.


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## Newt

rs79 said:


> Philips makes "agro lite", GE makes "plant and aquarium" and Osram Sylvania makes "Gro lux". They're basically the same thing.
> 
> 
> 
> The spectral output for these three tubes are as different a night and day. The only one worth a dam is the GroLux. I'd post the spectral output graphs but it'd be a waste of my time.
Click to expand...


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## rs79

The spectral outputs are a bit different. Off the top of my head the agro lite was a trichromatic tube, the other two looked roughtly the same to me, but it's hard to say as they don't list units on the Y axis ans all you can tell is the cirves are roughly similar. But, they work the same, and look roughly similar over your tank - the Osram is a tad more orange. I've used all of the for 20 years and have no favorite. I use what's on sale and mix them with C50s. I like the color of thar light. Warm whites work fine too though...

There really aren't any fluorescent tubes you can buy that WON'T grow plants. This is easily proved by trying things like "Kitchen and bath" or what have you. They all work.

Actinic and UV tibes won't work of course, plants need *visible* light.


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## rs79

I read the page @ aqua botanic. I'm not seeing any hard data about what bulbs are best there.

One more data point: around 1988 or so, somebody, I think it was Vinny Kutty posted on usenet that they were going to try a Mercury vapour lamp. All us said more or less "don't be an idiot, it's gone one hige blue spike and not much else. It's not going to work well at all". He ignored us (because these lights are CHEAP), tried it and had phenominal success. He was throwing garbage bags full of stem plants away every week.

In "theory" they should work very badly if at all.


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## ruki

Re: high pressure Mercury vapor bulb spectrum
















There's more than one huge blue spike coming from the bulb. Looks like enough red and blue to grow plants according to the standard theory.


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## rs79

That's not the spectra of the bulb he used though. It had a huge spike in blue
and not a lot of much else.

Kinda hard to read the above graph of count vs pixel. I'd sort of expect to see angstorms on the x axis.


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## defdac

rs79 said:


> I read the page @ aqua botanic. I'm not seeing any hard data about what bulbs are best there.


The PUR-efficiency table is what you are looking for, beneath "As an interesting exercise we could rank the bulbs according to their PUR efficiency ratio instead. The following table lists the bulbs so ranked."
I've made my own PUR-efficiency table here: http://www.defblog.se/permalink/1402.html



> "don't be an idiot, it's gone one hige blue spike and not much else. It's not going to work well at all". He ignored us (because these lights are CHEAP), tried it and had phenominal success. He was throwing garbage bags full of stem plants away every week.
> In "theory" they should work very badly if at all.


Actinics "one blue spike" have very high PUR-efficiency and grows plants very well, so someone must have gotten the theory all wrong...

BTW. I've come across a couple of different methods of calculating kelvin degrees out of a spectral distribution. I'm getting around 6800-6900K out of the Aquarelle... Anyone can confirm this?


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## ruki

defdac said:


> Actinics "one blue spike" have very high PUR-efficiency and grows plants very well, so someone must have gotten the theory all wrong...


Have you done this, grown aquatic plants under only blue light?

In green houses, narrow spectrums produce non-standard plants. Using only reds make plants tall and spindly, but encourages flowers. Using only blues tends to dwarf plants producing short and bushy. I assume the same would happen in an aquarium.


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## Newt

Ruki,
This agrees with what the Journal of Plant Physiology says.

To paraphrase:......good leaf development and compact growth (blue light) and stem elongation and color (red light)..........


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## fishstein

Has anyone tried the combination of a Sylvania Grolux with a bright bluish-white actinic bulb? The Grolux has a significant red spike, the actinics spike in the blue. And I'm thinking a 10,000K actinic with a very bright penetrating bluish white light might balance well with the subdued purplish glow of a Grolux.

1) How do you think this combination would perform for growing efficiency?

2) Do you think the visible light they would throw would balance in terms of a pleasing appearance? 

As I mentioned, currently I use the same bulb combination as Defdac and I get terrific growth and pleasing light. But I wonder how a Grolux would do with an actinic.


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## Newt

The GroLux has a spike in the blue but not as significant as in the red (true red I'd like to add). But the reason for this is that red light is easily absorbed by water and is not able to penetrate like blue light of the same intensity. So typically one should strive for double the red intensity compared to blue. That way it balances out more for the purposes of photosynthesis.

Personally I see no need for actinic lighting in a planted tank. There are too many better bulbs to mix with a GroLux.

GroLux Standard and GroLux Wide Spectrum:


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## fishstein

That makes sense. I'm curious to test a pair of Grolux bulbs with a pair of my other bulbs (same mix Defdac uses), but I don't think the blend of visible light will look very good, and I think the tank will look a lot less bright.


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## defdac

Red is attenuated faster in water, true, but that will not be noticable until several meters depth. My calculator will soon attenuate per frequency and also show the CCT-color from top to bottom. It has a very slight impact on PUR-efficiency since red bulbs will be somewhat less efficient to use.

So it's actually better to spend more money on bulbs shooting more blue than red efficienctly. GroLux-bulbs tend to have less efficiency since they just filter out green light (and the filter only produces heat). A more scientifically correct way of saying that is that they use less efficient phosphors for grolux bulbs.

Ruki, regarding growth patterns and light it actually boils down to changes in the far-red portion of the spectrum - that is where plants "look" to see for the best strategy growth pattern. Normally though, blueish lamps like Aquarelle tend to get then to spread out and nail foreground plants to the substrate and red lamps like grolux tend to make them spindly.


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## Newt

defdac said:


> So it's actually better to spend more money on bulbs shooting more blue than red efficienctly. GroLux-bulbs tend to have less efficiency since they just filter out green light (and the filter only produces heat). A more scientifically correct way of saying that is that they use less efficient phosphors for grolux bulbs.


I don't believe there is any efficiency involved in what phophours do when they produce/change the light. Sylvania uses the most expensive phosphour for red light. No other company produces red light as high in nanometers as does Sylvania because they wont shell out the $$$ for real red phosphour but settle on orange and red/orange.

I'm not even sure if what you are trying to say is valid. Others have stated the the GroLux is the epitome of plant lights.


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## defdac

Newt said:


> I don't believe there is any efficiency involved in what phophours do when they produce/change the light. Sylvania uses the most expensive phosphour for red light. No other company produces red light as high in nanometers as does Sylvania because they wont shell out the $$$ for real red phosphour but settle on orange and red/orange.


Expensive phosphour? If you must use expensive phosphors I guess you're trying to do fullspectrum bulbs with high CRI to get the color exactly right.

That is not necessary at all regarding plants. They need to be hit hard preferrably on the blue and red wing of the spectrum to trig the photosynthesis hard.

It might be that they use this "expensive" phosphour leading to much lower electricity to light efficiency than other bulbs - thanks for shredding some light over that =)

People tend to miss that there are many variables here. The phosphour does not just have to produce red and blue in about the right area of the spectrum, it need to do it efficiently with the energy at hand.



> I'm not even sure if what you are trying to say is valid. Others have stated the the GroLux is the epitome of plant lights.


It's not. But it's not bad either. You get spindly growth patterns and si-so growth rates and a very dark looking aquarium.

Other Grolux-type of bulbs like the Triton/Aquarelle/Aquastar have a pinkish color much like grolux, but have a much larger portion of their energy transfered to the blue portion of the spectrum. That makes them look more realistic but first and foremost they seem to have found a really ass-kicking collection of phosphors that transfer the electricy to plant usable light in a very efficient way.

It's easy to see. Have an aquarium with grolux only and switch to the same amount of a couple of year old Triton/Aquarelle/Aquastar and the immense pearling will speak for itself.


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## fishstein

I was only curious to compare because I've heard of so much talk about the Grolux bulbs being excellent plant bulbs and I've found it a bit hard to believe after seeing one up close and seeing how much brightness was lost. 

While I have never tried the Grolux, my experience with mixing the Phillips Aquarelle TLD89 10000K bulbs and Phillips ADV850 Advantage bulbs Defdac uses has been excellent. BTW, Defdac, your photos of a tank under various bulb combinations helped me make the decision - thanks again for posting these.

These bulbs are so efficient that 2 (one of each) with mylar in my 75 gallon hood are enough for to grow most plants well (and with high reflectivity parabolic reflectors enough to even grow red plants well with only 2 bulbs); 4 bulbs with mylar (2 of each) I can grow almost any red and green plants robustly, and I'm talking about balanced growth (not too squat, not too spindly, but just right). And the visible light combination is beautiful. They just blow away the high CRI full spectrum 6500K bulbs I was using before (and I tried several varieties over many years). 

The choice of bulb makes a tremendous difference.


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## Newt

fishstein said:


> I was only curious to compare because I've heard of so much talk about the Grolux bulbs being excellent plant bulbs and I've found it a bit hard to believe after seeing one up close and seeing how much brightness was lost.


Brightness to human eyes is green light so a plant bulb would not appear bright as it emits mostly blue and red light. Lighting 101.










Defdac, I'm still not following what you are trying to say.

The Triton isn't made any more about the same intensity of blue and a lower intensity of red than the GroLux (the standard not the wide spectrum) based on watts/nm/1,000 lumens. The Aquarelle is supposed to be a 10,000K bulb and should appear bluish. The GroLux Std appears purplish while the GroLux wide spectrum is the one that appears pinkish. Never seen the Aquastar. Must be a european bulb like the Aquarelle which is very difficult to find in the USA. I now of one source and they are $22 and for six months of use I'm not biting. It does have a tremenous spike in the blue and red/orange but it's very narrow. ADV850s must be european, too.


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## fishstein

Hi Newt,

I used to have the Tritons years ago in a palludarium and the Triton wasn't anywhere near as bright as the Aquarelle TLD89 10000K. Another thing - Kelvin does not equate directly with visible light. I've seen 10000K lamps appear more blue and less blue and some purple and bright violet. One reason the Aquarelle is so good - it is a VERY bright bulb - it is nothing like the Triton and Grolux - the Aquarelle is a very bright lavendar/very light blue color and the visible light it gives off is very complimentary to planted tanks. The Aquarelle is not really "European" - it is Phillips, which is a European company. It is carried in one or two smaller sizes in the US by a few retailers. I brought mine back from a business trip to the UK and I'm able to import them through my company. If there was enough interest, I could get together a nice order.

The ADV850 is available in the U.S. and is also a super efficient plant bulb. Both bulbs are vastly superior to any T8 bulb I've ever seen, and give off nicer visible light than the T5 bulbs I've seen.

Another good thing - both of these bulbs can be used for the life of the bulb and will lose very little performance - I'm getting about 2-2.5 years use per bulb. There's no need to replace them every 6 months.

After checking out all the options, and making my own highly efficient mirror aluminum T8 reflectors, I'm not going to bother getting T5 lamps and lights until more and better bulbs are available and prices come way down. I'm getting terrific performance from my bulbs and setup.

I have some extra ADV850 and Aquarelle in 48 in - PM me if you are interested. See for yourself, Defdac really knew his stuff when he chose these bulbs. I didn't buy them myself until I read a ton of research on these, saw Defdac's visible color photos and spoke with a botanist. Botanist gave them a big thumbs up.


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## Newt

I never said they weren't good bulbs.

I've heard many good things about the Aquarelle; just couldn't find them. 
Recently added to product line: $22 at www.drsfostersmith.com is the only source.
They say its a T12 and 40 watts. Other literature says they are T10 and 38 watts.

I use the PLL950s (55 watt CFs imported) along with grolux (and others) which I like for dawn/dusk lighting. But I'd like to find something better in a CF. I do like the 92 CRI of the 950s.

Kelvin ratings has more to do with the marketing dept.

Brightness only means it has an appeciable amount of green light being given off not how good it will be for plants.


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## fishstein

Actually Newt, drsfostersmith.com only has the following sizes:

Watts Length Diameter
15 18" T-8
20 24" T-12
30 36" T-8
40 48" T-12

I have T8 48 in. and I can give them to you at a better price. Brought these back from Cambridge, UK (don't ask what I had to do to carry a box of these out on my last day there). PM me if you are interested.


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## defdac

Newt said:


> I do like the 92 CRI of the 950s.
> 
> Kelvin ratings has more to do with the marketing dept.


Note that CRI is a value how well the bulb matches the kelvin of a black body radiator - so it's basically a kelvin measure too.



> Brightness only means it has an appeciable amount of green light being given off not how good it will be for plants.


True, but to get a somewhat natural looking aquarium the greens still needs to be there - as in the case of the 950s..


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## fishstein

Defdac,

Do you like the Phillips F32T8/TL950, which has a 98 CRI and 5000K as much as the Phillips ADV850? I haven't tried the TL950. I've found the ADV850, like the Aquarelle, is excellent for plant growth. The ADV850 may be a more efficient light (the Advantage series are supposed to be highly efficient and more environmentally sound, using less mercury).


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## defdac

I can't find any spectral distributions on the Advantage 850, perhaps because the ALTO-line uses recycled mercury and cannot guarantee the output or something. It seems to be a regular tri-phosphour though, like the Aquarelle.

The 950 seems to use other phosphors to generate a more continous spectral distribution, more like an ordinary filament bulb. Probably a whole lot less efficient since it will not produce as high intensity as the tri-phosphors. You will probably get nicer color from fish/plants though than the 850 or other triphosphors.

That's just an educated guess though.


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## fishstein

Makes sense. Though I have to say - I've used 98 CRI 6500K bulbs before - I found there really isn't that much of a difference from the ADV850 - it renders pretty closely to the high CRI bulbs. In the end, doesn't matter a lot, because I use the ADV850 as a complement to the Aquarelles, and it's a very nice combined visible light which makes the plants and fish look great. 

I've noticed an interesting animal behavior effect with the Aquarelles - they so effectively highlight blue/purple fin tips that many of our fish display more to each other and engage in more breeding behavior. Fortunately there are enough rocks and plants that there's plenty space to avoid bad outcomes from displays which escalate into fights.

I've also tested the ADV850 for plant growth efficiency, and it does very well, so I'd be afraid to switch it out unless I hear very good things about the TL950 from a reputable source.


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## detlef

Daniel,

not the best of spectral plots but that's what I've found re. the ADV 850 www.aquabotanic.com/images/light_fig2.jpg

Couple questions though:

1. Does anyone know the wattages they sell the ADV 850 in? I came across a t5 alto bulb carrying the product name F54T5/850/HO/Alto TG. Looks promising but is it the same superb alto bulb?

2. Daniel, Arcadia has a "Marine White Lamp" out, rated 9500K, highest energy output around 400-480nm, good colour rendition, supposed to be used for marine environments. I would appreciate if you could run PUR efficiency testing on this one also! 
www.arcadia-uk.info/product.php?pid=14&mid=11&lan=en&sub=&id=4

3.The action spectrum (AS) was derived from the green Anacharis/Elodea. Red plants would have a much different AS I guess requiring more energy in the blue, green and may be yellow part of the spectrum vs. a green plant to compensate for the red light which they can't efficiently use (because they reflect reds). 
In trying to find the best suitable lighting for growing R E D plants should'nt we know the PUR ratings calculated from a red plant's AS curve as well?

Thanks and best regards,
Detlef


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## fishstein

I don't know if the bulb has the same spectral properties (you'd have to test to be sure), but I did confirm with Phillips that this is the their T5 version of the ADV850. If the T5 bulb has the same properties, it would be one of the best T5 bulbs for plants. 

I'll add that the 850 puts out nice color, and you can see red plants very well, but I do prefer the Aquarelle color mixed with the 850. I've been wondering what would be an analogous bulb to the Aquarelle in T5 in terms of not only growing efficiency but visible light color. Let me know if you find one.


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## farrier

Hi i need some help I have a new lux light meter with waterproof probe. I put the probe on the botton of my aquarium and the reading was 450-500 light intensity is this high, med or low ???
I would like to know what plants i can put my aquarium also have o2 Will someone help we


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## defdac

detlef said:


> Daniel,
> 
> not the best of spectral plots but that's what I've found re. the ADV 850 www.aquabotanic.com/images/light_fig2.jpg


Thanks Detlef, that was the one I used to make the claim that the ADC 850 probably is a regular tri-phosphor (and thus ought to have high PUR-efficiency like the Aquarelle/Aquastar/Triton).



> 2. Daniel, Arcadia has a "Marine White Lamp" out, rated 9500K, highest energy output around 400-480nm, good colour rendition, supposed to be used for marine environments. I would appreciate if you could run PUR efficiency testing on this one also!
> www.arcadia-uk.info/product.php?pid=14&mid=11&lan=en&sub=&id=4


That is also a tri-phosphor and probably have a high PUR-efficiency - I need the wattages and lumens-output to calculate the exact PUR-efficiency though.



> 3.The action spectrum (AS) was derived from the green Anacharis/Elodea. Red plants would have a much different AS I guess requiring more energy in the blue, green and may be yellow part of the spectrum vs. a green plant to compensate for the red light which they can't efficiently use (because they reflect reds).
> In trying to find the best suitable lighting for growing R E D plants should'nt we know the PUR ratings calculated from a red plant's AS curve as well?


In my beta calculator you can upload whatever action spectrum you want. I have one for Zooxantheallae and it have a rather similar AS to green plants.

If you find one for red plants let me know and I would be glad to upload it into the calculator.



> Hi i need some help I have a new lux light meter with waterproof probe. I put the probe on the botton of my aquarium and the reading was 450-500 light intensity is this high, med or low ???
> I would like to know what plants i can put my aquarium also have o2 Will someone help we


As I answered in your other thread, that is extremely low light. It's the equivalent of a 75% reflected 7 watts bulb over 150 gallons.
My guess is that the probe must have been shaded when you did the measure?


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## Newt

I found out that www.aamsco.com carries the Aquarelle. The 48 inch is a T8. DrsFosterSmith didnt print their catalog correctly.

You can also get the ADV850s and PLL950s


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## fishstein

Hi Newt,

That is a great relief, because I hated having to lug the Aquarelles from England. I hope they have them at a better price than DrsFosterSmith, which sells them for a whopping $22 each. Are they available singly? Will check it out later tonight.


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## fishstein

Newt - I just checked and AAMSCO lists them as T-12, not T8. Did you speak with them?


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## Newt

Yes, today. They have a webmaster do their web page and clear issues when they find enough.
They are T8 but have none in stock. They are going to call me tomorrow with a cost.


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## fishstein

It will all depend on whether they have a big shipment coming in from Phillips. If they have to special order because they don't get a lot of requests for Aquarelle, and they don't have a Phillips shipment coming in now, they will charge moocho $ and may make you order a box of 12 to 25 or more. That's what happened when I checked with a big Phillips distributor. Hopefully they will not try to pass on special order freight costs to you and will allow you to purchase without buying boxes. I'm hoping, because then I'll have a US source for them.


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## Newt

They didn't call today but the box size is 6 pcs.

If they knew there were a lot of potential cutomers then they would stock up.
They did mention that it was not a big ticket item with them. Perhaps not enough people know that they import Philips european bulbs.

Goodmart.com lists the Aquarelle but has Ammsco as the lamp distributor:
http://www.goodmart.com/products/bulb_fluorescent_tube_gro_lux_aquarium.htm


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## ruki

Newt said:


> If they knew there were a lot of potential cutomers then they would stock up.
> They did mention that it was not a big ticket item with them. Perhaps not enough people know that they import Philips european bulbs.


Perhaps not enough people know that on paper this looks like a really great bulb.

Remember, in the USA people can't seem to help blindly purchasing long CF fixtures :heh:


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## Newt

Just so interested people out there know what the spectral output looks like; here it is:









too bad its not in color


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