Yeah, a 90 is a pretty deep body to illuminate -- I could see SPS growth being weaker near the bottom.. Does the AI fixture give you an idea of the amount of intensity being used to power the lights? I know, at least with the Cree's, the lights are typically underpowered a decent amount from their max capacity -- I'd figure this would be similar here..

Also, I've gotta know -- in your sig, does that mean 300 square foot shark tank? Wild.

-Corruption