That will not provide the par and spread needed for an sps dominant 90 gallon. I owned that light for many years. It's fine for a 55 gallon or maybe a 75 gallon if it's mixed and sps placed carefully under it. For a 90 gallon with sps everywhere you'll want at least 6 bulbs if you're going pure t5ho.
That's exactly what my friend told me!
I was going to use retrofit t5 with led hybrid but am tempted to buy this light to get the tank going. It's only $50 I could always re sell it. Any opinions? dang I need help. I'm obsessed lol and impulsive!