Objective lighting measurements

[lorenz0]

^^^^
t5's can be run for up to a year but like MH you loss alot of output. Your die hard t5 guys will run bulbs 4-6 months max just to keep maximum output from the bulbs. For MH+T5's really aren't there for growth but for pop so you can still keep your bulbs up to a year.

I personally think t5's are more expensive in the long run, esspecially when your replacing 6 bulbs twice a year which costs $200 or more, let alone running a 10 bulb system.

With the amount your save on energy, your just spending more on bulbs. So imo, MH's are cheaper to run.

as for the original question, light is not the only issue to have to look into when it comes to corals. Flow is a big factor as well. In some cases just to keep one type of coral you will have to place another under a ledge or in a lower flow area.