How hot are they?

[fortheloveofcrabs]

How hot, exactly, is a 150 watt 10,000K MH bulb? The reason I ask is because I was wondering if that CoolWorks micro chiller would be strong enough to cool my 5.5 gal with that ontop, in a sealed hood, with 4, 4 inch fans?

[jasontatro]

Can't fathom why you would put a 150w MH over a 5.5 gal tank.

 

Good luck with all that.

[fortheloveofcrabs]

Clams and LPS corals, that's why. That, and I can get 150 watt bulbs, but not 70 watt.

[toefu]

sorry to say, but on a 5.5 gallon, 70 watt is plenty strong to keep just about anything that is sold out there.

[Korbin]

The 150 will heat your tank up plenty. For reference, you can feel the heat on your hand if you hold it about a foot below the bulb. Plan on having an open top and being able to adjust the height of the light. A strong fan (vornado or similar) even from across the room will blow away much of the heat, but you will still get lots of greenhouse effect within your tank. I wouldn't go so far as getting a chiller, just rely on fans. They can do a lot. You will also NEED an auto topoff device because you will be getting lots of evaporation. IME, you can completely forget about putting it in an enclosed hood. Think of it this way - my 150 in a horizontal pendant gets so hot I can't touch any part of the fixture with my bare hands for more than a couple seconds.

Keep in mind that light is only one factor in keeping clams. Stable water conditions (pH, alk, calcium) are also vital.

Also keep in mind that you won't be able to put actinics on there. And a 10K 150 watt bulb, IMO, is about twice as bright as a 20K. You might consider a 20K unless you really like the look of a 10K.

 

I agree that your metal halide options for a small tank are very limited and the availability of 70 watt bulbs is discouraging. I would opt for the 150 watt as well. Maybe consider a single-ended 150 watt? Good luck!