Need some help with MH clearance

[deskjockey]

I would like to upgrade my lighting on my 65gal. Im currently running
2-96watt PC's and would like to add 2-175watt MH's and maybe run the PC's with 2 actinics. But my problem is clearance. I have a canopy that only leaves 6" above the waterline and 5" from the glass covers. Once everything is installed Im guessing the bulbs will probably be 3 inches from the glass. Is this way too close? Would double ended bulbs be a better alternative?

Any help would be greatly appreciated, Thanks
Deskjockey

 

[tim000]

I dont know if this will help but I have a 175w MH about 7 inches above the water line in my little 15gal, and the temp seems to stay right around 79 degrees.

 

[t-byrd]

i'd like to know the minimum clearance over acrylic,
would the heat crack the top?

 

[CraigLampe]

well, I would think that, yes the MH is going to be putting some major heat into the hood, but if you have some throughput of air to cool, you should have no problem... the true test is whether you can safely touch this glass cover/partition after the whole situation is "up to temperature"...

if it is too hot to touch, I would think that a large splash of reef SW may cause it to cool quickly and crack... This may be a MAJOR problem if the divider is already stressed by being under tension, and then a crack could be DISASTROUS! i.e. front glass bows out and shatters!!

I would proceed with caution, but I think all you need is good cooling, every one of our tanks would have some sort of major problem if the cooling fans stopped in the middle of the day!!

 

[deskjockey]

oooohhhhhh I didnt think about that! 8O 8O
I dont even want to imagine it! maybe Ill just stick to my PC's or have another canopy made......damn wish I had the stuff to do it myself