Bulb spacing???

[chele]

I've decided on a 40br for my reef tank. My husband is going to build the stand and canopy for me. Now all I have to do is figure out the lighting.

 

What I want is 2 175w MH bulbs at opposing ends centered in the hood and 2 96w PC 50/50 lights 1 front 1 back.

 

Question is... Is this workable??? Space wise, I know I have the room in the canopy... Problem is I really don't know if these quarters will be too cramped. I intend to put exhaust fans in either end of the canopy to keep things cooled and I will also be using a heat resistant backing/ paint for the inside of the canopy.

 

Anyone have any idea on how far apart PC and MH need to be? I know they shouldn't touch but is there any sort of minimum safe distance? Any ideas or suggestions welcomed.

 

TIA,

Chele

[Christopher Marks]

There's no real guidelines...just make sure you space them as far apart as is reasonable. The cooler the bulbs are, the longer they will last; you don't want a metal halide lamp killing your pc bulbs.

[wetworx101]

Yes, the killer thing with PC&MH combos is that if the PCs are too close to the MHs, the phosphors in the PC run hotter...changing the frequency of ther light output...and eventually causing premature death. You got a whole lotta light goin into that hood there. You could eliminate one of the MHs and still be fine (keep one in the middle). That would free up some cool air space (and cash). Or go with three MH's...say screw the heat and live with it, but make one of the MHs a 20,000K bulb...

[chele]

I think I'm gonna go with 2 20k MH bulbs and 2 96w 10k bulbs.. instead of the 50/50.. I just wish they made 18k MH.. I have an 18k pc and I just love the shade in my tank..

 

Over all.. Would you say three to 4 inches would be enough space between bulbs??

 

Tanks,

Chele