Distance between 150w fixture and water?

[Anonymous]

Simple question, but searches have revealed a myriad of answers. What distance is ideal between a 150w MH (+4x24w T5) fixture and the water? I have the fixture at 10 inches right now (no water in the tank yet, I'm kind of guessing roughly where it will be), but a test run has shown there will be a certain amount of glare hitting us where we sit watching TV. I was thinking of lowering the rack slightly so that the fixture will be only 7" off the surface, which, helped by the canopy I have (see build thread), should reduce glare.

Does anyone see any problems with that? Given that it's only one 150w bulb, over a 64g tank, I don't think it should add too much in the way of heat...

 

[Anonymous]

It should be fine.

I've had them closer than that.

 

[Anonymous]

Cheers Louey - I'll lower the rack tomorrow.

 

[Anonymous]

Should be just fine especially since it's a fixture and not enclosed in a canopy

 

[Anonymous]

Should be just fine especially since it's a fixture and not enclosed in a canopy

What Gresh said. My fixture is about 10inches from the surface Tom and it seems to be jsut fine. Now go take pictures for us

 

[Anonymous]

 

[D.W.L.]

My current 150w pendant is about 10in. also but in a hood. When I ran hoodless and used a similar fixture, it would have only been a few inches off the water. Of course with the smaller reflector in them, the spread was not as good. Still ok for my 28in long tank. Just had to watch which corals were in the ends sections.

 

[Anonymous]

Thanks DWL. I might end up lowering the fixture again once I can see where the water level is (once I finally get it wet!).

 

[Anonymous]

Tom, I have run 150w halides as close as 5 inches from the water, as long as there is adequate circulation heat should not be a massive trouble. Just mke sure that the bulbs are behind a glass splash cover- you dont want an accidental splash to pop one- broken glass in your substrate is a baitch! My big tank has 3X250w halides and they are about 8" off the water. i'd love them closer during winter as the cost of heating that volume of water is steep.

 

[Anonymous]

Thanks Andy. I might well lower them another couple of inches. There's still a little glare and I think I can risk it, given the canopy is less a canopy and more an open, deep rim, so there should be plenty of air circulation. Plus it's a fixture considerably smaller than the tank's top surface area.