I’m planning to replace the two MH lights I have with T5 lights to save on electricity & heat. So I want to get a 4 bulb retro T5 kit and attach to the inside of my canopy. But I’m uncertain if I should get 48" or 36" lights.

My tank is ~110g (48w, 24h, 21d) . One reason I’m reluctant to get 48" lights is that I have a 4" wide glass lip running along the inside of my tank. So only the central 39" of the tank is unobstructed. If I get 48" lights, then the 4" on each end will have to shoot through this glass lip.

I guess I could also try to get rid of the lip on the two sides too, which does not not look too hard.

Any opinions?

Thanks.