Short and sweet, I'm building my own hood and need to know how high the lights need to be away from the water and also how many fans you use and the placement. Thank you.
The VHO can be pretty close to the water as they don't get that hot but I had mine in a 10" canopy as I was using MH also. As far as the fans, I used a doorknob hole drill and made the holes. I have 4 x 4" fans in my canopy, 2 blowing air in and 2 on the other end taking it out, I did this to run the air across the top of the tank.
What type of VHO ballast do you have? With an electronic ballast the bulbs stay a lot cooler but with a tar ballast they get pretty darn hot. I have an Icecap and I can easily grab a bulb and they are only warm to the touch so I would think you could mount them pretty close to the water, mine are about 5"
Hey toptank,
What kind of moonlight do you have going there? I am looking for one to go with my tank for night time which do not require me to mess with my canopy. Just a hang on type.
Most say from 3-6 inches. Mine are about 4-6 inches. One fan is good for me. It will also depend on your surface turbulance. If the surface is moving fast you will have more splash up and may need them higher.