# What do I need to know about LED?



## john.shephard26

Hi, I consider my self moderately experienced fish tank owner and until now I've been using compact neon light but recently I got a much bigger tank and I thought that its logical to do a step up and start using MH.Since I haven't been around for some time here I noticed that LED is very popular so it made me wonder whats that about?I've start browsing and saw lots of elaborate threads which actually confused me a bit (too much in so many places) so I gave up reading at the end.
If I want to start using LED what is it that I need to know in the beginning.
I guess I'd like to see or read every thing in one place here about LED cause you must admit, it is much different and more complex than other kinds of lights.


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## john.shephard26

Anyone please?


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## ObiQuiet

My opinions.

1. Commercial out-of-the-box fixtures powerful enough for growing plants are still very $$$
1a. Some manufacturers have mix-n-match light strips
1b. Finding a commercial fixture that will put out enough light for your needs still requires careful reading of the specs.
2. Many small tank kits (in the < $150 price range) now come with LEDs, which if doubled up could be sufficient to grow plants


3. Today, the most cost-effective way to get plant-gowing LED fixtures is DIY.
3a. LEDs have a very narrow spectrum, unlike incandesent and flourescent, so careful choices and mixing of types is important.
3b. The individual LEDs are somewhat expensive, best to get them via ledgroupbuy.com or similar
3c. Such sites provide help with what to buy, so you don't have to design the light yourself.

4. LEDs do save power and do not put out much heat unless overdriven. These are their advantages.
5. LEDs themselves will last forever unless overdriven. Power supplies, switches, etc, are still subject to premature failure.

6. LEDs, being point light sources, do create more shimmering effects


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## Seattle_Aquarist

Hi john.shepard26,

Watch for some exciting changes in DIY LED in the next couple of months; kits.

I did some calculations and although there is some savings in electricity consumption the real savings is in replacement bulb costs. I computed the payback to be a little over two years. I took some PAR readings of a compact fluorescent vs LED in an 17" deep tank w 2+" of substrate and they put out almost identical reading.

Which one is LED and which one is 2X 36 watt 6700K CFL?


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## john.shephard26

About those two pics ...honestly I can't tell the difference...I guess I need to read a bit more about LED...I'm curious...how much LED light would I need to light a tank that is 33x17x17inch or 44galons of that is otherwise high light tank?


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## icepick96

john, I'm in the same boat you are on LED lights. Not sure if I should DIY a light fixture or throw some cash at a pre made fixture. Bottom line is I'm having a hard time getting info on LEDs vs T-5. Specifically how much light is right. My background is in reef tanks where more is generally better when talking about lighting. With a planted tank it seems there is a fine line with just enough to having too much. One fixture I'm looking at is made by Finnex Ray II: Ultra Slim High Output LEDs. I just don't know if one fixture will cut it or if I need two.


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## bigstick120

Ive been looking at the Finnex Ray II as well. I have seen PAR charts for them, just cant find them right now! 

What you need to look for is the size of the fixture and the distance to the substrate to get an accurate PAR rating.


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## NYREPS

I got the finnex ray 2 about a month ago they been working pretty good ,my boy Brayan from finnex hooked me up before they came out double 65k


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## NYREPS

Sorry double 7k


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## icepick96

NYREPS, Could you share some tank info please? Tank size, fixture size, and what plants you have. Also does that fixture have a good spread of light front to back?

bigstick120, http://www.plantedtank.net/forums/showthread.php?t=184294

I'm assuming that was the chart you were looking at.

P.S. Sorry john.shephard26 for hijacking your thread


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## Michael

icepick96 said:


> bigstick120, http://www.plantedtank.net/forums/showthread.php?t=184294
> 
> I'm assuming that was the chart you were looking at.


According to the original post, "PAR data taken through open air." This makes the data meaningless for a tank filled with water, which is the way most of us use them.


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## icepick96

So Michael how does a water filled tank effect the par readings compared to a non filled tank? assuming other factors are the same.


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## Michael

Measurements of natural sunlight I took in one of my ponds at noon in the month of June showed a 50% decrease in PAR at a depth of 24" compared to the surface. Just above the surface PAR was 1,700 umol; at 24" PAR was 800 umol.

Artificial light does not maintain PAR at depth nearly as well. You can see a decrease of 50% in just 10" of water, and in 24" of water you can easily get an 80% to 90% loss of PAR. You can see data at this thread: http://www.aquaticplantcentral.com/...tic-plant-club/80982-par-data-collection.html

The spectral output of the lamp can make a big difference. Lamps that put out a lot of blue light maintain PAR better at depth, because blue light travels better through water than other wavelengths.

I have trouble interpreting the graphs in the post on LEDs, but my opinion is that PAR loss is going to be many times greater measured in water rather than in air.


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## NYREPS

My tank is mr aqua 33.6 gallon the demention is 24.8x17.7x17.7
My finnex double 7k led light is 24 inch 
And I just set this tank up two weeks ago and have ADA aqua soil still cycling 
It's has 3 types of plants giant baby tears in the back and dwarf hair grass and hc Cuba in the middle after 2 weeks I see they are settling in very nicely I was gonna order another strip but one strip will work fine ..I have pictures of before and it looks like it cover the whole tank ...very brite


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## herns

heres a good reading.

http://www.plantedtank.net/forums/showthread.php?t=160396&highlight=LED


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## Michael

Great link! The data shows basically the same rate of decrease in PAR with depth.


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## jdmstop

According to hoppy on APC, he tested a 24" finnex ray 2 and it is consider a high light fixture when sitting at about 12 to 15 inches, it will get about 80 par. I am going to try this for my ADA 60p

Sent from my ADR6400L using Tapatalk 2


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## dillondays42

There are some major differences between LED signs and what you don't know could end up hurting you...in the wallet. If you don't know what to watch out for, you will probably not be happy with your LED display, maybe not at first, but you will end up unhappy.


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## rod

One problem I found with LED lighting that no one has mentioned, that I've see yet. Is that if you use them with a glass covered tank water droplets form on the bottom of the glass cover. With CF I never noticed this. I believe this is because of the glass cover getting hot with the CF. Has anyone else noticed this?


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## NYREPS

After 52 days of growth I think the finnex RAY II is doing its job don't you guys think ? With no algae at all








day 1








day 52


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## Aquaticz

Distance from substrate please & thanks for sharing


Sent from my iPad using Tapatalk HD


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## NYREPS

Aquaticz said:


> Distance from substrate please & thanks for sharing
> 
> Sent from my iPad using Tapatalk HD


What do you mean by that ? You want a closer picture?


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## Michael

I think Aquaticz wants to know what the distance from the lamp to the substrate is.

The tank looks great!


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## NYREPS

Oh ok thanks Michael !

Well my tank is 17.7 inch tall
And there is a slop in the back about 5 inches and 2 inches near the front .

I was worry at first because my tank is also 17.7 from front to back too and was thinking I'm gonna need 2 lights or have to hang them up to get the light to shine on the whole tank but it worked out well great and I didn't need to hang them or get 2 lights.


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## Aquaticz

Yes Thank you Michel.. That is exactly what I wanted to know. The distance from the light to the substrate.
I have order a 48 inch Ray II and will first try it on a 55 gal right on top. If that works I will get another for a 75 gal tank. If it does not work out on the 55 I am sure it will be just right for my 75
Trying to move away from 4 2 X 55 watt CF on the 55 and 4 x 55 on 75. Should get it this week I think. I will report back to al the threads about LEaD and post my experience. 
Thank you

PS
I was also concerned as you were about the spread of the light given the width of your tank. Great to hear it did the trick for you



NYREPS said:


> Oh ok thanks Michael !
> 
> Well my tank is 17.7 inch tall
> And there is a slop in the back about 5 inches and 2 inches near the front .
> 
> I was worry at first because my tank is also 17.7 from front to back too and was thinking I'm gonna need 2 lights or have to hang them up to get the light to shine on the whole tank but it worked out well great and I didn't need to hang them or get 2 lights.


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## Aquaticz

Ok so received the ray II and it is not going to do it for me. The quality of light is to flat for my liking on a larger tank. It is nothing more than aesthetics I am sure the light will grow plants because I have one on a 6 gal tank (fuge). I am used to CF 4 X 55. ( On. A 55 gal and a 75 gallon tank both DIY A&H reflectors) What I miss with this fixture is the " visual pop" of the reds and greens. 

I now own three Finnex fixtures, I won two of them .
I do like the combo of both the led and the CF. 
That looks awesome to me but with by current lights I think I would have an algae problem. I am thinking of using these FINNEX fixtures in combo with either CF or most probably a Catalina fixture. Funny but I have not read of anyone using these LED fixtures in combination with the other types available to us. Have you? 

I do not want high light tanks, more on the medium side but not low light either as I have a 40 and a 29 gal that are.

Hoppy if you read this what are your thoughts about a combo? I am thinking that possibly a custom Catalina one bulb fixture along with the Finnex might be the way to go. 

All comments are welcome 

Sent from my iPad using Tapatalk HD


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## Flear

correct me if i'm wrong, ...

when i was looking up lighting and LED vs. Florescent lights, ... it was strange.

light intensity, Lumens, PAR, PUR, ... could not find anything to compare PAR & PUR differences with LED vs Florescent lights.

when it came to Lumens, (only good for human visuals, not good for plants) light intensity vs watts, ... seems to be 1:1, ... what i could find showed 50watts of LED was producing about the same Lumens as 50watts T5HO.

Florescents had a tendency to point out lumens to rate light intensity. and had little to nothing to say about PAR
LEDs had a tendancy to talk about PAR, and had little to nothing to say about lumens.

but personal suggestion, ... spread your light out, a single band of light across the middle of your tank leaves for some very dark areas in the front and back.


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