Metal Halide 2 or 3 lamps?

[ezy33]

Metal Halide 2 or 3 400 watts on a 6' 180 [acronym:1cd8707a21="Gallon"]gal[/acronym:1cd8707a21]? Or 3 250 watt lamps?

Last fall I answered a add for a reef tank and was just thinking about buying the lighting. The add stated 2 250 [acronym:1cd8707a21="Metal halide light"]MH[/acronym:1cd8707a21] mogul base and 3 [acronym:1cd8707a21="Very high output fluorescent"]VHO[/acronym:1cd8707a21] T12 Actinic. After a few moments on the phone I found out the whole system was $300.00. When I arrived it turned out that [acronym:1cd8707a21="Metal halide light"]MH[/acronym:1cd8707a21] lights were 400 watts way too much for my 55 [acronym:1cd8707a21="Gallon"]gal[/acronym:1cd8707a21]. So as I get ready to pull my 180 [acronym:1cd8707a21="Gallon"]gal[/acronym:1cd8707a21] fresh water from the wall to install my 180 reef I'm thinking about the lighting. Would 3 250 watt lamps be better or would 2 400 watt be ok? I will scrap the [acronym:1cd8707a21="Very high output fluorescent"]VHO[/acronym:1cd8707a21] for 4 65 watt Actinic PCs.

As Metal Halide lighting is new to me and the tank will be under a stair case. What would be the best distance from lamp to water for a 24" deep tank? Has anyone used E-Bay to buy lamps with any luck?

Thanks in advance.

[lando]

General rule is one [acronym:7f59951624="Metal halide light"]MH[/acronym:7f59951624] lamp per two feet of lenght you would want to light. Ideally, 3 x 400watt [acronym:7f59951624="Metal halide light"]MH[/acronym:7f59951624] in a 180 would be great, due to the depth of the tank. Depending on what you plan to keep, 3 x 250 would be better then 2 x 400, [acronym:7f59951624="In my opinion"]IMO[/acronym:7f59951624]. It will give you more even, consistant light across the lenght of the tank.

[Phyl]

I run 2x250 over my 4'x2'x2' deep 120. I would get 3 of whatever you get for your tank. You can't beat the color of the 400s though. If you want [acronym:b02b16497f="Small Polyped Stoney"]SPS[/acronym:b02b16497f] I'd go 400s. If you are going to keep [acronym:b02b16497f="Large polyped Scleractinian (stoney) coral"]LPS[/acronym:b02b16497f]/softies/etc. I'd do 250s otherwise you'll have tremendous bleaching problems even at the lowest levels.