light rack for frag tank

i was just wondering about the hight of mh 250 wattx2 it will go on a 12" deep system?

i suppose it would depend on what your putting in the tank. Thats a lot of light for 12" so i guess I would shoot for something like 8-10" Might have heat issues though. I have 250w over my 55 and it can be hard to keep the temp inline even in the winter, although our apt is usually super warm

he is right, you will get a lot of heat issues with that shallow. I would say stay 1 foot of the surface and put some fans in.