# T5 HO Bulbs



## Bryeman (Aug 24, 2009)

I know there have been a lot of threads on this subject, but just wondering if anyone has new input on a good, solid 6,000K-6,700K choice for T5 HO bulbs? From the research I've done, it seems like most of the bulbs nail the 430-453nm spectrum peak, but most fall below on the red peak where preferred absorption would be in the 640-665nm range (most graphs of bulbs seem to show a 590-620nm peak). Just wondering if anything has changed and what people currently recommend? Looking for 2 bulbs to complete my current experiment. I currently use Aquaticlife bulbs in the 8x39w Aquaticlife fixture. Love the fixture, but not sure of the bulbs and would like to try a different bulb brand for comparison as well. My current setup is 2 - 6000K, 4 - Roseate, and 2 - 10,000K. I plan on putting 2 more 6000/6700K in place of 2 of the Roseate.


----------



## bosmahe1 (May 14, 2005)

Currently, I use 2 Geismann Daylight (6000k) and 2 GE Starcoats (6500K) on a 46 gallon Bowfront that is about 21 inches high. The Geismanns are about a year old, when I am ready to replace them, I will use 2 additional Starcoats. The price is good and I like the color. They don't look as yellow as the Geismanns. I tried the Starcoats because I saw them mentioned on a Reef site as having a high PAR value.

http://www.aquariumspecialty.com/catalog/product_info.php?cPath=28_39_448&products_id=2622


----------



## bosmahe1 (May 14, 2005)

Additional info on GE Starcoats.

http://www.1000bulbs.com/images/PDF/ge-46748-specs.pdf


----------



## Bryeman (Aug 24, 2009)

Thanks for the info. I'll do some research on these. Have you noticed any actual plant growth differences between the bulbs or just visual differences?


----------



## bosmahe1 (May 14, 2005)

Bryeman said:


> Thanks for the info. I'll do some research on these. Have you noticed any actual plant growth differences between the bulbs or just visual differences?


I haven't done a direct comparison between the two but, I removed a couple of hygro species from my tank because the weekly pruning became very tedious. My lights don't have great reflectors like Tek has either. All I can say is, the GE Starcoats give me more performance than I need and the fact that they cost $12.00 is a bonus. Below is a link to PAR comparisons done by reefers. The fact that the Geismanns have a PAR of 325 compared to a PAR of 340 for the Starcoats, sold me on trying them. So far, I haven't found any reason to disbelieve their findings.

http://216.187.96.54/vbulletin/showthread.php?t=44531

Hope this helps.


----------



## Bryeman (Aug 24, 2009)

bosmahe1 said:


> I haven't done a direct comparison between the two but, I removed a couple of hygro species from my tank because the weekly pruning became very tedious. My lights don't have great reflectors like Tek has either. All I can say is, the GE Starcoats give me more performance than I need and the fact that they cost $12.00 is a bonus. Below is a link to PAR comparisons done by reefers. The fact that the Geismanns have a PAR of 325 compared to a PAR of 340 for the Starcoats, sold me on trying them. So far, I haven't found any reason to disbelieve their findings.
> 
> http://216.187.96.54/vbulletin/showthread.php?t=44531
> 
> Hope this helps.


I have 2 Geismann Aquaflora's inbound to try based on other threads I've been reading. I WILL also be ordering 2 of the Starcoats that you mention soon as well. It will be interesting to see how they perform/look given the price! Thanks again for your ideas/info. My plants are generally growing very well, but I like experimenting with the lighting to look for that "little extra".


----------



## bosmahe1 (May 14, 2005)

Bryeman said:


> I have 2 Geismann Aquaflora's inbound to try based on other threads I've been reading. I WILL also be ordering 2 of the Starcoats that you mention soon as well. It will be interesting to see how they perform/look given the price! Thanks again for your ideas/info. My plants are generally growing very well, but I like experimenting with the lighting to look for that "little extra".


I've experimented alittle, I have a few T5HO 39 watt bulbs still lying around:

Current 10000K and actinic that came with the Nova Extreme 4x39 watt
Current 6500k and pink bulb that came with another Nova (2x39 watt)
Geismann 6000k Mid day
GE Starcoat 6500K

If I were to do serious experimenting, I would get a PAR meter. Maybe when I can't think of anything else to buy.


----------



## Newt (Apr 1, 2004)

Very few fluorescent bulbs have red peaking at the proper nanometer range i.e. 640 -650nm.
One reason is because the red phospher is very expensive. However, if the intensity is strong enough this really doesnt matter too much althou the proper range is preferred.
The GE 5000K Starcoat bulb is actually a better all around bulb for plants than the 6500K. The 6500K does have stronger emissions in blue area BUT it also has a big green spike and is void of red. I dont like the green hue.


----------



## Bryeman (Aug 24, 2009)

I have put my 2 - Aquaflora's in, and I can tell by the look and the spectral output that these are a better light compared to the brand I've been using. I'll be able to tell more this weekend when I have time to actually time the pearling rate of these bulbs compared to what I have documented in the past. They seem to be a huge improvement though, and I'm going to have to watch my photo period again so I don't disturb the algae demons from there sleep!

I'm going to let the current setup ride for a while and see what happens. Eventually, I will get two more Aquaflora and two more 6000k or 6500K type bulb and call it good. I beleive some people told me to do this from day one, but I'm stubborn and the learning process has been fantastic!


----------



## bosmahe1 (May 14, 2005)

Newt said:


> Very few fluorescent bulbs have red peaking at the proper nanometer range i.e. 640 -650nm.
> One reason is because the red phospher is very expensive. However, if the intensity is strong enough this really doesnt matter too much althou the proper range is preferred.
> The GE 5000K Starcoat bulb is actually a better all around bulb for plants than the 6500K. The 6500K does have stronger emissions in blue area BUT it also has a bigger green spike. I dont like the green hue.


Sounds like I should try a GE 5000K. It would be interesting to see how it looks in combination with the GE 6500K. The GE 6500K looks blueish to my eyes, that's what I like about them. The Geismann 6000K looks to yellow to me. It works out OK mixing it with the GE 6500K IMO. I've read some accounts that the blue peaks tend to make plants bushier and the red peaks tend to make them grow thinner and taller. My stems grow taller than I like.


----------



## bosmahe1 (May 14, 2005)

Well, it looks like the GE Starcoat 5000K has an even larger spike of Green and the red spike is only slightly taller than in the Starcoat 6500K. The blue spike is rather short so, I'm not sure what I would get out of the 5000K.

http://www.1000bulbs.com/images/PDF/ge-46747-specs.pdf

Tell me if I am missing something.


----------



## Newt (Apr 1, 2004)

This is from the GE website:

http://www.gelighting.com/na/busine...ty/downloads/covrguard/80579_t5_covrguard.pdf


----------



## bosmahe1 (May 14, 2005)

Newt said:


> This is from the GE website:
> 
> http://www.gelighting.com/na/busine...ty/downloads/covrguard/80579_t5_covrguard.pdf


Thanks Newt. looks like something to try.


----------



## Bryeman (Aug 24, 2009)

Low cost for sure. Nothing close to the original Planta bulb that everyone was talking about for a while. The original had about the best red spike I've seen on any graph. I'm going to make sure I try a set of these GE bulbs.


----------



## Newt (Apr 1, 2004)

I'm not too sure any more about the accuracy of the Planta graph:









OR if it is a different bulb than shown in the attachment:


----------



## Bryeman (Aug 24, 2009)

Newt said:


> I'm not too sure any more about the accuracy of the Planta graph:
> 
> 
> 
> ...


From the research I've seen, it's different from what is called the same bulb today. They changed it. That's what it seems anyway. Not saying the original graph was accurate, but if so, it's the best I've seen yet.


----------



## Newt (Apr 1, 2004)

The picture on the box of the spectral graph is either off on the nanometer scale or the coloring is off.


----------

