How high above the tank is everyone running their halides?

[FishInABarrel]

I have a 406w oddyssea fixture with 2-39w actinic, 1-39w purple, 1-39w pink t5 and a 250w 10k halide. I have it hanging on chains from the ceiling so I can adjust it. I've had problems with it heating the water and currently have it about 21" above the tank with 1f temp change.

How high does everyone else run their lights?

How high can I go? (Tank is 21" tall)

[ridetheducati]

Go as high as you like. Aim for maintaining 100-200 PAR on sand bed.

[FishInABarrel]

I don't have anything to measure par right now. I was kinda wondering if going too high would lose to much light. My open brain is on the sand and opens right up during the day, so I'm guessing it's happy with the light.

[Timber77]

i have mine 18 inches high running 400 hqi radium's. no heat issues. i do have a fan on a controller that kicks in to keep the air moving across the top of the tank.

[shifty51008]

mine are about 14" above the water

[machote]

U consider the level of the bulb or the reflector? To get the idea

[shifty51008]

mine is from bulb to water

[FishInABarrel]

Mine is 21 inches at the bottom of the fixture. So prob 22-23" to the bulb.