Aussie Acan Placement

[Tim Plow]

I recently got a couple of Aussie acans and wanted to know what you guys suggest on placement and flow. I have (3) 400 watt MH. Currently, they are on my sand bed, but I was wondering if I could get better coloration and growth if I move them up at all.

 

[tmz]

I have 2 250watt 14 k and 220 actinic on a 120gallon(48x24x24).I keep several aussie acans fom mid tank on down without a problem.