MH, How much Clearance?

[bunzaroo]

I am going to ditch my PC's for a MH's undercanopy setup. What is the minimum clearance that everyone recommends, fan placement? Thanks

 

[Sk8r]

9 inches from water surface is a good distance. You DO want a glass shield between MH and water splash, plus cooling fan at either end is a good idea.

 

[bunzaroo]

How should I direct the fan , at the water surface or at the actual lights, sorry Rookie here!!

 

[Sk8r]

At the lights. The glass shield stays cool enough to touch, thanks to the fans. On my bought-fixture, two standard good computer fans, one blowing in directly onto the bulb, one exhausting out at the other end, which also helps a bit with the dust problem. They're wired to go constantly: they could be wired to go whenever the lights go on.

And I can't overemphasize how important that tempered glass shield is: the mh lights are like movie projector bulbs---you want not to get your fingerprints on them: handle them with tissue or the like; and a splash of water hitting one when it's on will shatter it.

 

[Nuuze]

9-12 inches is good distance. Point the fan to blow between tank and lights to circulate the heat.

Be aware you will have more water evaporation.

 

[bunzaroo]

How should I direct the fan , at the water surface or at the actual lights, sorry Rookie here!!

 

[che25]

I keep mine at about 8.5" above the water. The fans are installed with the fixture. I'm using the following setup:

http://www.marinedepot.com/ps_ViewI...ting_Saltwater_Aquarium_Supplies~vendor~.html

 

[ahullsb]

I agree with the height stated above. Keep that fan pointed right at the lights. I used an infrared thermometer on my glass shield and the temp was over 200 degrees! Sk8r is lucky, I burn my arm on it occasionally.