Ideal depth for a grow out tank?

[jh2pizza]

I have an extra tank I am planning on drilling out and using for a grow out tank. What would the ideal depth be? I plan on using t5 bulbs. The tank itself is 27" high, but I will be able to set the water level at what ever I determine, the be bulbs will have to stay around 24 to 27" from the bottom of the tank.

 

[uztaryn]

I like 12" on grow outs... you will be moving stuff around in the tank all the time and will need to be able to reach everything easily. I would strongly consider a shallower tank than the 27" one. I realize you don't have to fill it all the way up but you still have to reach all the way down.

 

[hollback]

Or build some racks to keep the corals near the surface. This also provides you twice as much space having, two levels. Keep the lower ligh corals underneath the rack.