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View Full Version : how close lights to water surface?


FreedR
08/21/2007, 04:49 PM
I recently bought a 75g RR tank with a plywood hood that has 2x 175w MH and 2x 48" actinics. The wiring on the hood does not meet code, to say the least, so I'm considering making a new hood. (That, and the hood isn't exactly aesthetically pleasing to the wife.)

How close can I get the lights to the surface of the water? I imagine the answer is "as close as you can without getting them wet," but I'm curious what other people have done.

ludnix
08/21/2007, 06:18 PM
My light is 9" from the water surface currently.

NanoReefWanabe
08/21/2007, 06:37 PM
in my 20 gallon the my 150MH is 4" from the water,

you have to be the judge yourself i would say though...too close and you wont light up the whole tank...too far and you get enough light into the tank..

basically turn the lights on and see how high they have to be in order to fully light the whole tank...

argetni44
08/21/2007, 06:40 PM
i have maintained a 90g tank at one point with a metal halide fixture that sat roughly 4-5 inches above the surface of the water, and luckily for me the water didnt touch the lights because of the plastic shield on them... id say depending upon the filtration system and your return, you may be able to place them about 7 inches away or so uncovered, but any closer, and you'd need some sort of protection for them.

argetni44
08/21/2007, 06:43 PM
i actually saw the water boucing off the surface at one point from the convergence of my powerhead and the return from my filter... i have awesome surface agitation which i love, but the lights could have been in jeopardy if they werent covered

hllywd
08/21/2007, 08:23 PM
These ended up about 6"...

http://reefcentral.com/forums/showthread.php?threadid=1163749&perpage=&pagenumber=1

I've also got a 175W MH 3" above my 30. It gets splashed all the time. I take it out once a month or so wash it under running water, dry it very well and reinstall. This has worked great for me for several years and never a broken bulb.

Tim:cool: