how far to put mh bulb from vho bulb

[mark42]

hi i am upgrading my lighting on my 125gallon tank .currently have 2 vho 1 anctic 1 50-50 total watt 360 just purchesed 3 250 mh retro kits . my question is how far apart should the mh bulb be from the vho i dont want the heat from the mh to burst my vho is this a concern or not? thanks

 

[The Pirate]

Turn the MH so the raidient heat isn't directed twards the VHOs. Something like this.

 

[mark42]

pirate thanks for the reply but my vhos are 72 inched long i cant do my mh like you have yours

 

[King Jason]

If you put the VHO's under the MH's I would do this.

VHO's as close to the water as is safely possible, maybe 4 inches? Then put the MH's 12" above the water. That gives 8" leeway. I would also put fans blowing across the top of the VHO's. I would think this should keep this cool so the VHO’s won’t crack or burst.

 

[Anonymous]

I ran them inches (like 2) from the halides, I always run my halides very close to tank, inverse square law applies, so I keep them low, last tank was 3" from water, this tank I havent bothered to drop them yet, but I may later....


I do keep them towards the rear, and front of the halide, and fans to cool them, never had a problem with this setup.

 

[King Jason]

I ran them inches (like 2) from the halides, I always run my halides very close to tank, inverse square law applies, so I keep them low, last tank was 3" from water, this tank I havent bothered to drop them yet, but I may later....


I do keep them towards the rear, and front of the halide, and fans to cool them, never had a problem with this setup.

What happens when a fish splashes water onto your bulbs? Aren't you worried about them shattering?

 

[Anonymous]

They hiss, I've had it happin, didnt hurt anything, in fact I clean the salt creep from them once every couple weeks.

Actually had a snail plug an overflow, the clip on fan I was using turned into an outboard motor, the iwasaki 250w's I was running at the time were cool to touch by the time I had the return pump turned off, lesson learned, dont put fans inside canopy lower than the tank itself