Yup, just water on a paper towel. Make sure it's off first :razz:

I use vinager on a paper towel.

Steve

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To the best of my knowledge, there isn't a whole lot of light that can be lost with the varying distances right? I mean, you'd have to talking several feet before it would be noticable right? I just moved mine up to about 10 or 12 inches because I was getting a bit of splash.

light looses intensity by the inverse square rule:

1/d^2

i keep my 400w SE 8 inches from water surface
some light salt after 3 months but no explosion yet :)

Tak

the higher the fixture the more spillage you get.

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actualy it does make a big difference.

Steve

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Well then, how much difference? :biggrin: I see the formula above but I'll need more of an explaination.

These links show the light drop off for various distances from the bulb to the water surface. They test reflectors but you guys are using reflectors anyways so the results would be applicable.

http://www.advancedaquarist.com/issu...03/feature.htm
http://www.advancedaquarist.com/issu...03/feature.htm

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well at 1" from the bulb I had over 2500 PAR and at 6" I was down to about 1200 PAR so almost 50% for 5" on one of my tests.

Steve

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Wow, thats crazy! I had no idea that air inhibits so much light. I might have to make an adjustment or two on my fixture now. Thanks guys.