Do I need 48w or 96w of T5Ho ?


Junior Poster
Feb 2, 2010
I am starting to think about what lighting I am going to buy and I was wondering if I should "bite the bullet" and buy an expensive 4 bulb fixture or just stick with a 2 bulb fixture.

Here are my plans....

Tank = 33 Gal 25"x18"x18" with Pressurized CO2

Tank will be in the corner and viewable from front and one ideally heavily planted on the far side that tapers down to carpet of some kind (preferably HC lawn).

This is all new to me so when folks say newbies don't initially realize how much work is involved with pruning when they have high light....well that is actually encouraging to me. I have tried to grow plants in a fish only tank with very limited success so the idea that if I do it correctly this time that I could actually grow plants so well that I have to prune them....well that is exciting ! :)

But back to my original question....

I am looking at buying a 24"- 2 x24W fixture because(as I understand it) that much T5HO lighting is more than enough to grow whatever I want. However I was wondering if there may come a time when I may want more light and need to add a 2nd fixture. If that is the case then I was thinking maybe I should just buy a 4 bulb fixture and only run 2 lights in the beginning. The thinking is that if I ever wanted to have more lighting I would already have it ...or if I want to make a mid-day burst (which I have my doubts as to whether or not that is really beneficial). I also plan on hanging the fixture as I don't like the idea of the lights sitting on top of the open aquarium especially when it comes time for maintenance and my hands are in the water.

I was leaning towards the AquaticLife fixtures.... and if I got the 4 bulb model it would have a built-in timer and allow me to control 2 bulbs independently. Also the 4 bulb fixture would seem to me to have better "coverage" even if using only 2 of the 4 bulbs as they would be spaced further apart than they are in a 2 bulb fixture (1 bulb on, 1 bulb off, 1 bulb on, last bulb off).

Any thoughts or suggestions for an over-whelmed newbie?

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Guru Class Expert
Mar 5, 2009
You summarize it well, I'd go for the 4 bulbs fixture for all the reasons you said, if money is not an issue, it won't harm


Lifetime Charter Member
Lifetime Member
Jan 15, 2009
Go with the 4 bulb fixture. You'll have better spread if you use the outer two bulbs. Once you get above the 18" tank width you might need more spread but that's not the case here. The Tek 5 units come wired for outer two bulbs and inner two bulbs. I suspect this is standard, but you may need to adjust yours to do this. If nothing else, the 4 bulb fixture saves you the "what if" later on and there's nothing that says you need to use the extra two lamps, or even put them in.