How high should I put light rack

[bmooney31]

I have a 12" deep frag tank and have 2 250 watt SE lumenbright reflectors over it, and was wanting to know how high would you guys put the lights? Right now I have it at 12 to 13 inches above the water. do you guys think thats a good height or should I go higher. My SPS seem to be faded in color. Now I will say I have a alge outbreak which makes me think its also due to high phosphates. I just set up a BRS reactor on it with the HC GFO in it. so we will see what that does.

 

[dakotasreef]

There are many possible variables that could cause that. I do not use MH but think that might be a little too close. Now are they faded or browned out? Fading can be from too much light or lack of nutrients. Browning can be from excessive nutrients or not enough light. Also the color temp of the bulb can play a role it coral coloring also. Depending on what type of lighting the corals were under previously, you might have to raise the reflectors quite a bit and slowly acclimate them over a few weeks.

 

[Paul_N]

I have lumenbrights and the recommended height is around 16" above the water surface with tanks that are 20" or so tall. With a tank only 12" tall I would at least put them at 18" above the surface if not more. Make sure you are measuring distance from the actual bulb and not the bottom of the reflector to the surface of the water. Marc at melevsreef did a great par test with different reflectors including Lumenbrights:

Melevsreef.com - PAR Measurements Taken

 

[Troylee]

i had my t5s about 8" above the water on my 12" deep frag tank..."bleached!!!!!!" moved them up to 18 and things look better.... i would say at least 18" on them mh....