Acrylic and M/H lighting?

dead beat reef · 09/06/2006, 11:31 PM

I have a 60 gal. Its 18 inch deep. I run PC lighting. Softie tank.
If I change to a M/H lighting sys. Do I have to keep the bulbs
12 inches above the water? I like a low profile canopy.
Do you think the acrylic will discolor? Big concern. J

GixxerChip · 09/07/2006, 07:19 AM

I have had a 70 watt halide on my 12 gallon tank for a year now and it is about 6 inches off the water (used to be 4) and i have had no dicoloration in the acrylic. I dont think it should be a problem, any buddy else had a problem with discoloration?

seattlerob · 09/07/2006, 07:41 AM

I don't think the main concern is discoloration, but if the MH is too close to the top of the acrylic tank, you may warp the acrylic on top from heat. This may be especially true if you cover the openings. Distance above the water would be in relation to the wattage of the MH system, as more watts will burn hotter.

I have 2x250w MH above my 90. They are approx 4-5 inches above the top of the tank and I have not had any issues. My canopy is 12" tall. Given the profile of most MH reflectors/pendants, I'm not sure how much lower profile you could go. Best to measure the height of the MH system before you buy, and determine how much clearance there will be once you mount in your canopy.

hth,
rob

silverwolf72 · 09/07/2006, 11:51 AM

If your warping the acrylic I would imagan that everything in your tank would be dead by then. Usualy height is determined by how much the tank water is being warmed by the lights unless you run a chiller. The lower you run your lights the warmer the water is going to get.

dead beat reef · 09/08/2006, 10:51 PM

The PCs are 4 inches above the center brace. With the fans
off the temp. is about 108 f. With your M/H on and the fans
cooling on 175 or 250 watts. Hows your temp. reading on
the center brace? I want to do a DIY set up with 2 175s
and the 2 96 PCs for actinic. Lots of fans? I have zero exp.
with M/H so all help is most welcome. Thanks dbr.

09/06/2006, 11:31 PM	#1
dead beat reef Registered Member Join Date: Jun 2005 Location: New Mexico Posts: 279	Acrylic and M/H lighting? I have a 60 gal. Its 18 inch deep. I run PC lighting. Softie tank. If I change to a M/H lighting sys. Do I have to keep the bulbs 12 inches above the water? I like a low profile canopy. Do you think the acrylic will discolor? Big concern. J

09/07/2006, 07:19 AM	#2
GixxerChip Registered Member Join Date: Jan 2005 Location: Plano, TX Posts: 17	I have had a 70 watt halide on my 12 gallon tank for a year now and it is about 6 inches off the water (used to be 4) and i have had no dicoloration in the acrylic. I dont think it should be a problem, any buddy else had a problem with discoloration?

09/07/2006, 07:41 AM	#3
seattlerob Registered Member Join Date: Oct 2005 Location: Seattle Posts: 464	I don't think the main concern is discoloration, but if the MH is too close to the top of the acrylic tank, you may warp the acrylic on top from heat. This may be especially true if you cover the openings. Distance above the water would be in relation to the wattage of the MH system, as more watts will burn hotter. I have 2x250w MH above my 90. They are approx 4-5 inches above the top of the tank and I have not had any issues. My canopy is 12" tall. Given the profile of most MH reflectors/pendants, I'm not sure how much lower profile you could go. Best to measure the height of the MH system before you buy, and determine how much clearance there will be once you mount in your canopy. hth, rob

09/07/2006, 11:51 AM	#4
silverwolf72 Registered Member Join Date: Jul 2005 Location: Lake Forrest CA Posts: 1,732	If your warping the acrylic I would imagan that everything in your tank would be dead by then. Usualy height is determined by how much the tank water is being warmed by the lights unless you run a chiller. The lower you run your lights the warmer the water is going to get.

09/08/2006, 10:51 PM	#5
dead beat reef Registered Member Join Date: Jun 2005 Location: New Mexico Posts: 279	The PCs are 4 inches above the center brace. With the fans off the temp. is about 108 f. With your M/H on and the fans cooling on 175 or 250 watts. Hows your temp. reading on the center brace? I want to do a DIY set up with 2 175s and the 2 96 PCs for actinic. Lots of fans? I have zero exp. with M/H so all help is most welcome. Thanks dbr.