# Calling all lighting gurus. Got a ? for ya



## flashbang009 (Aug 6, 2009)

Hey guys and gals,

I have a total of 4 t8 bulbs over my 75 gallon. They've been overdriven due to lack of intensity. However, i'm still having (as in i had this problem before they were overdriven) algae on the glass. I read another forum where someone said they had algae problems and inadequate growth, but upon raising the lights over the tank, the conditions drastically improved. This makes sense to me because you don't have the accumulation of light from the reflector directly hitting the glass of your tank (if the lights are placed on top of the tank...like mine). So. Here's the $75,000 question. Would raising lights higher off of the tank help, and if so how far. 

Specs of lights:
4x~55 watt t8 (2x 3500K and 2x 6500K)

I'm not looking for advice on how to stop the algae, if i have too much light, etc etc. Just if raising the lights would be better in general for the tank.

Thanks!


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## medicTHREE (Feb 5, 2010)

Without the rest of the details of this tank, there is no way to answer this question appropriately.


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## flashbang009 (Aug 6, 2009)

pressurized co2, pps pro, ferns (bolbitis, nl and regular java fern), pygmy chain sword, blyxa, and some moss with fluorite. I realize the ferns are slow growing thus needing less co2, ferts etc. The question however is that if the lights are given more room to disperse light, would it help the plants grow more. For instance, in takashi amano's gallery, the lights are about 2 feet above the tank. Different lights obviously, but same idea.


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## medicTHREE (Feb 5, 2010)

4 bulbs should be giving a good spread over your tank. How far apart are these bulbs now? All raising bulbs up does is reduce intensity.

Amano is using MH lights and HAS to have them up that high to get them to cover the whole tank. You have bulbs the length of yoru tank and should be covering most of the front to back space with bulbs, so you will only reduce intensity by raising them.

I raise the bulbs above my 75 g riparium but that is so the riparium plants get light and to reduce the light in my tank, as it is a low tech no co2 tank with T5HO lighting...


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## Newt (Apr 1, 2004)

Its easier and probably more effective to shorten you photoperiod (duration of lights 'ON').

Overdriven bulbs is not a good idea especially when already over used. It can shift the spectrum of light. When overdriving (put in simple terms) you have more bombardment of the mercury into the phosphours which decay. You can wear out a layer of phosphour quicker than another and loose or shift that spectrum of light that the bulb should normally put out. It really not a good way to get more intensity/light out of your bulbs. Plus it makes them run much hotter.


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## flashbang009 (Aug 6, 2009)

Yeah, i understand the drawbacks. For $3.00 a bulb, i'm not too worried about it, and my plants seem to love it. The GDA is the only problem, but i had that before i overdrove the lights. I think...

And the smile for the day... :flame:


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## Newt (Apr 1, 2004)

GDA on the glass is one of the hardest to deal with. Look in the algae forum for a thread titled Method of Controlled Imbalances.


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## flashbang009 (Aug 6, 2009)

Alright i will. Its hard to wait the recommended time for not scraping it off =;, have to resist the urge though.


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## madtundra01 (Jan 27, 2010)

I would check your phosphate levels. I had GSA on my 55 gal, dosed up the phosphates to 2ppm and the algae was gone in a couple days.


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## svenhipsta (Dec 16, 2009)

flashbang009 said:


> Hey guys and gals,
> 
> I have a total of 4 t8 bulbs over my 75 gallon. They've been overdriven due to lack of intensity. However, i'm still having (as in i had this problem before they were overdriven) algae on the glass. I read another forum where someone said they had algae problems and inadequate growth, but upon raising the lights over the tank, the conditions drastically improved. This makes sense to me because you don't have the accumulation of light from the reflector directly hitting the glass of your tank (if the lights are placed on top of the tank...like mine). So. Here's the $75,000 question. Would raising lights higher off of the tank help, and if so how far.
> 
> ...


refraction off the surface would increase so your light level would decrease so that would help with the algae. you could also drop your water level to equal effect. is your tank getting direct sunlight striking it?


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## flashbang009 (Aug 6, 2009)

No there's no sunlight. I think the algae problem was due to ferts. I'm fixing it now


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