metal halides from top of tank

twomenandatank · 07/15/2007, 03:18 PM

My Dad and I built our own stand and hood. The LFS said that the MH's could be 10" off the tank to keep the tank cooler but now i have a chiller. So how off the top over the tank should my MH's be for my 120?

DarG · 07/15/2007, 04:32 PM

Depends on the wattage, type and reflectors to a degreee. Ballpark range is 6" - 12". Halide bulbs lose intensity with time so to compensate alot of experts advocate starting with a higerh height and slowly lovering the height over time. For example, maybe 10" when new and lowering, in 2 or 3 stages, down to 6 or 7" nearing the end of their useable life.

07/15/2007, 03:18 PM	#1
twomenandatank Registered Member Join Date: Feb 2007 Location: illinois Posts: 59	metal halides from top of tank My Dad and I built our own stand and hood. The LFS said that the MH's could be 10" off the tank to keep the tank cooler but now i have a chiller. So how off the top over the tank should my MH's be for my 120?

07/15/2007, 04:32 PM	#2
DarG Registered Member Join Date: Dec 2006 Posts: 5,515	Depends on the wattage, type and reflectors to a degreee. Ballpark range is 6" - 12". Halide bulbs lose intensity with time so to compensate alot of experts advocate starting with a higerh height and slowly lovering the height over time. For example, maybe 10" when new and lowering, in 2 or 3 stages, down to 6 or 7" nearing the end of their useable life.