I have 2 Maximas and 1 Crocea and 1 Bta in a tank that is 24 inches tall and they are doing great and it is lit with just T-5's. THe crocea is on the sand bed and the maximas are about 6 inches up from the sand bed and the BTA is all the way to one end and isnt even under the brightest bulbs or one with a reflector. This might make for some interesting reading for you.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=724967
http://www.reefcentral.com/forums/showthread.php?s=&threadid=724967