PDA

View Full Version : What is the optimum distance from the water for bulbs?


214vette
10/08/2008, 12:15 AM
Okay so I am rather new to salt water. I have a 135 gallon 72 x 18 x 24 display tank. The current canopy is only about 6" tall so I am going to have a friend customize it for me. I have 3 250 watt SE coralvue 10k bulbs and 2 72" T12 VHO super actinic bulbs. All will be placed under one large reflector (no idea what brand, it came with the ballasts I bought). I have pictures below of the ballasts and sockets.... Anyways, how many inches off the water should these be installed? I need to know how tall to build the canopy and he's doing it this weekend....

Rest of the system in case it matters:
40 gallon sump and a 12 gallon fug. ASM G3 skimmer. 150-175 lbs live rock. 1/3 hp JBJ chiller (not installed yet but it is on standby depending on what the temps do with the new lights). JBJ ATO. The tank has dual overflows built in. 2 Koralia Hydor 4's with upgraded props. There are no fish in the tank as of yet. I have had the system cycling for 2-3 weeks so far. Thanks for the advice

http://i448.photobucket.com/albums/qq210/jusbechillin/fishstuffforsale1014.jpg
http://i448.photobucket.com/albums/qq210/jusbechillin/fishstuffforsale1016.jpg
http://i448.photobucket.com/albums/qq210/jusbechillin/fishstuffforsale1015.jpg
http://i448.photobucket.com/albums/qq210/jusbechillin/fishstuffforsale1017.jpg
http://i448.photobucket.com/albums/qq210/jusbechillin/fishstuffforsale1018.jpg

psteeleb
10/08/2008, 07:25 AM
there is no set or optimum answer to your question; tank configuration, reflector qaulity, bulb types, heat, and safety considerations all come into play.

Closer = more light into tank but also more heat, and more chance of salt creep

farther = less light into tank, less heat and less salt creep

better reflectors allow for being able to mount the lights farther away with less light loss. For example: I was running a flat relector (basically polished aluminum) on the inside of a hood about 12" above my tank. I changed to the Lumabright reflectors, moved them to about 16" above the water and get more light in the tank and less heat a plus plus for me.

Generally speaking the closer the better, but you have to be aware of the salt creeep issue and water splashing both safety issues. Heat can be dealt with but at some expense, fans chillers air space etc.

your set up sounds nice, I would also do something with a 6" hood as that is just too close for MH's. I'd say give yourself ~10 -12" of space, but a lot depends on how that canopy will work. If you use a front access you will want them higher so you can get inside and under them. If the top opens with the lights attached, lower will work but I'd avoid going any closer then 8" for heat and salt spray/creep reasons

214vette
10/08/2008, 09:03 AM
My reflector is a 72" long sheet of reflective metal with the edges bent down. If you took a hexagon and cut it in half thats what It looks like.
I think I will have him make it another 6" tall. I will attach the bulbs to the top lid which will be hinged. In the middle of the canopy at the 6" point will be another hinge for access into the tank. The bulbs will sit about 11" off the water. Sound good? Do I need some type of splash guard at this height?