Walmart Shop lights - advice? :)

[Stara'lfur]

My new set up:

- 46 Gallon Aquarium, 48L x 15W x 15H
- Low light plants from Mgamer
- Non CO2, low tech tank

So I bought two shop lights from Walmart for like 10 bucks each. They each use two T8 32W bulbs. Since I was aiming for 1.6 WPG, I currently have 3 bulbs hooked up.

Two questions:

1) Now, the shop lights are sitting right on top of the glass cover on my tank. Part of one of them is over a small portion of the tank that is not covered - a bit of space surrounding the filters. Is this dangerous, since the lights are not made for aquariums, with the evaporating water and all? Should I be hanging the lights over the tank, which would look bad, but I think it's possible..?

2) Since there is no reflective surface inside the lights, am I not really getting the 1.6 WPG using the three bulbs, and should I instead use all four bulbs which would technically put me at 2.0 WPG if it was all getting in? I really want to avoid algae growth and I don't mind slow plant growth, but I do want at least my 1.6 WPG.

Thanks guys!

 

[Stara'lfur]

Argh I just realized I can't edit the original post. I can't believe I messed up with the lighting calculation up there. So it's currently at 2 WPG, might downgrade to two bulbs make it 1.39 watts. Agh! I had done the original calculation when I thought the tank was 60 gallons, but I got it home to find out it was 46 gallons.

*headdesk*

Should I keep it at 2 WPG given that they are "inefficient" shoplights, or go with two bulbs for 1.4 WPG? I have a smaller fluorescent light (pinkish, unknown wattage) I could add in addition to the 1.4 WPG to help out.

 

[SuBXeRo]

t8 lights dont put out as much useful light from what i understand, it varies between bulb sizes. DIY fixtures like what you have done is more of a trial and error scenario. Anywho, i would stick to the general idea of watts/gallon for a fluorescent bulb.

OK! next, the light fixture, chances are is white inside and out. White is the most reflective color that you can have, putting polished aluminum aside, as far as paint goes, white is the color. Ontop of that, not having a parabolic reflector, you will lose some of the useful light. DONT WORRY, most light fixtures dont have parabolic reflectors, most just have a shiny top to reflect the light down. hence my whole shpeal above about light output and it being trial and error.

I wouldnt leave ur lights right ontop of the tank unless u have glass below the light, like a versa top, this will help prevent moisture from getting up into the light. After time, constant evaporation will corode and ruin the fixture.

If you can prop the fixture up, it would probably bebetter, plus its nice to get some airflow here and there.

back to my first point, trial and error. 2wpg in theory is alil much if you dont have enough plants or co2. Good thing, algae grows kinda slow, if you see algae start popping up, reduce the wattage. This is very much a trial and error game for everyone with any light fixture, you always want the maximum amount of light before algae growth begins. Play around with it and keep us posted.

 

[Stara'lfur]

t8 lights dont put out as much useful light from what i understand, it varies between bulb sizes. DIY fixtures like what you have done is more of a trial and error scenario. Anywho, i would stick to the general idea of watts/gallon for a fluorescent bulb.

OK! next, the light fixture, chances are is white inside and out. White is the most reflective color that you can have, putting polished aluminum aside, as far as paint goes, white is the color. Ontop of that, not having a parabolic reflector, you will lose some of the useful light. DONT WORRY, most light fixtures dont have parabolic reflectors, most just have a shiny top to reflect the light down. hence my whole shpeal above about light output and it being trial and error.

I wouldnt leave ur lights right ontop of the tank unless u have glass below the light, like a versa top, this will help prevent moisture from getting up into the light. After time, constant evaporation will corode and ruin the fixture.

If you can prop the fixture up, it would probably bebetter, plus its nice to get some airflow here and there.

back to my first point, trial and error. 2wpg in theory is alil much if you dont have enough plants or co2. Good thing, algae grows kinda slow, if you see algae start popping up, reduce the wattage. This is very much a trial and error game for everyone with any light fixture, you always want the maximum amount of light before algae growth begins. Play around with it and keep us posted.

Thanks! They are white inside, indeed. Well since 2WPG in theory is a little much, but these lights aren't as efficient, it's a bit lower than 2WPG right? Or is it still pushing it...

 

[petluvr]

I have these same lights on a 29 and on a 55 and both are open water, no glass covering, just the lights setting right on top of the open tank. Been like this for a year or so and no problems yet. I can grow ANYTHING in my 29. The 55 on the other hand seems to grow only low light plants and then VERY slowly.

 

[Stara'lfur]

After hearing some advice from others I think I'm going to go for the 1.4 WPG. But if anyone else has anything different to say let me know. !