I have mine 3-4 inches off the water. The closer the bulbs are, the better my coloration is. The problem is, I use a Reeflux/Luminarc set up and the bulbs are very intense out of the box, while they dull out really quick after about 4 months. Thats when the lights get closer to the water.
I measured the Quantum Flux and out of the box the readings are in the 800's at the surface of the water and 8 months later they are 400
