T5

[Reefcraze_1]

I have narrowed down my lighting options to either:

4 bulb Ice Cap fixture with SLR and a 660 ballast which overdrives the bulbs.

Or

Sunlight supply 6 bulb with SLR.

Right now it's a question of intensity and bulb replacement, the fixtures cost about the same.

How much time is taken off the bulbs life if it's overdriven but the bulbs are kept cool by a fan (heard this helps them last) ?

What would be the difference in lighting intensity between the 6 bulb and the overdriven 4 bulbs?

[PEMfish]

You will lose about half the bulb life overdriving them. You will not double the output.

What size tank, and what do you want to keep?

[Intranick]

Honestly -- if you have a wide enough tank (13" is wide enough for 4 bulbs so i'm assuming 18" is wide enough for 6) I would personally go with the 6

Look man, I have not personally overdriven light bulbs, but I have over-clocked computers, even with proper cooling, any time you push manufacturer limits, you're putting unneeded stress - I have watched overclocked computers to 110% do good for the first half hour of any task, but as they warm up they lose stability -- im imagining it does the same with bulbs but instead of immediate heat and stability, it means you change the function of the bulbs sooner -- go with the 6 if you dont need the 4 overdriven. kk?

[Reefcraze_1]

I know it wont double the output, it will however run a 39w bulb at 60w.

I have heard as long as you keep the bulbs cool it wont drastically reduce the bulbs life, like instead of a bulb lasting a year and a half, it will last just over a year.

[PEMfish]

Just run it at the rated 39w.

[jski711]

I would get the 6 bulb tek fixture. That's what I run and can grow sps on the bottom of my tank. Imo overdriving is only good to use if you can't fit as many bulbs as you would like to keep over the tank. Hth

Jake

[Reefcraze_1]

What kind of SPS are you keeping on the bottom of your tank? Cause I'm interested in keeping a few corcea and maxima clams on the sand bed.