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View Full Version : 1 or 2 250w's for 3' tank?


justme97
05/06/2009, 12:06 PM
So I'm trying to figure out lighting needs for my upcomming 58 gallon (38w*18d*20h) and trying to decide if I should get a lighting fixture with one or two 250w mh bulbs (with florecent supplentation).

It seems some fixture makers make 3' hoods with one bulb, some with two...so I'm a bit confused as to which to go with...2 almost seems like overkill but maybe I'm wrong?

Entropy
05/06/2009, 12:18 PM
Canopy or no canopy? For a hanging fixture I would probably go with two. You will get a better light spread and since it is open heat will not be as big an issue. In a canopy I would go for a single and a really good reflector. Paint the inside flat white (all of it) and get the biggest reflector that will fit inside so the spread will be as much as possible. Assuming you will have a bit of space on either side and the front (I have six inches on either side) you are really only lighting a 24x12 area.

justme97
05/06/2009, 12:40 PM
Thanks. No...it's open top, gonna have the fixture hanging from the ceiling. Ug do they really generate that much heat....haha is my ac bill gonna go up a lot??

kretzkiller
05/06/2009, 01:25 PM
you definitely need two

Toddrtrex
05/06/2009, 02:38 PM
Over my 58 I have 2*250 (( 20K bulbs )), I couldn't imagine just having one over it. I know that I wouldn't care for the darker corners.

Mine sits on top of the tank, and don't have any real issues with heat -- clip on fans over the sump takes care of that. My home stereo heats up my living room more then the lights do, that is what kills my A/C bill.

Entropy
05/06/2009, 04:20 PM
If you are hanging them I would go for two. The bulbs heat the tank more than the room itself, but when hanging you generally have a lot better air flow around the fixture so not as much heat dumps into the tank. My tank is about the same size (in gallons) and my single 250w halide raises the temp about 1.5 degrees over the six hour light cycle (with a 120mm fan pulling air out), but I have a completely enclosed canopy so it holds the heat in more than a open unit would.

justme97
05/07/2009, 08:21 AM
Ok, thanks everyone. I'll go with a dual fixture, probabaly a ab oceanlight (w/t5s) or a few pendants....