I have a Marineland T5HO 4 Bulb 214 Watt Fixture on my 55 Gallon.

I might get another (Do you guys think that will be too much light on a 75/90 Gallon). 8 Bulbs

The big thing that I am worried about is the Lightning.

I read in a book that T5 lights can only penetrate into 18 inches of water. While Metal Halides can go down 39 inches.

I do not want to have to get Metal Halides. I currently have problems with them.

I would definitly go with the 90 gallon but it is 3 inches taller so I am worried about the corals I keep on the bottom of the Tank not getting any light and dying on me (Torch, plate, etc).

Thanks in advance for any help on this decision,
Steve