What height of HQI 250's

Big Boy69 · 07/16/2007, 10:21 AM

Currently, I'm running 8 - T5"s over my 120.
I'm going to make a setup to run 2, 250w HQI pendants with
4, T5 bulbs.
How high should I run the pendants above the water?
When I ran Moguls, I ran them at 10" above the water.

reefingagain · 07/16/2007, 05:35 PM

10" is safe most ppl have it between 7-11" Make sure to acclimate your corals since there use to t-5's you can start with a 4hr photo period and increase 1 hr per week or have the pendant high and slowly bring it down or a combination of the two.

reefworm · 07/16/2007, 07:53 PM

I agree - from a heat standpoint 250w 8.5"-9" over an open top can be handled by one 4" cooling fan blowing over the water. Temp rise after 12 hours only 1.5~2 degrees. I know that's too much, but right now I'm just testing the heat issue. 6-7 hours appears to be a consensus on appropriate amount of light.

token · 07/16/2007, 08:03 PM

Quote:

Originally posted by reefworm
6-7 hours appears to be a consensus on appropriate amount of light.

Is that photoperiod with supplementation from another light source such as the OP's T5's?

reefworm · 07/16/2007, 09:43 PM

correct. 6-7 hours for the most intense light overlapped with other light sources such as those you mention. I plan to run the T5 actinics about 10 hours. Apparently more than those hours of MH is too much intensity, kinda like noonday sun for most of the day.

07/16/2007, 10:21 AM	#1
Big Boy69 Registered Member Join Date: Jan 2005 Location: Allentown, PA Posts: 1,213	What height of HQI 250's Currently, I'm running 8 - T5"s over my 120. I'm going to make a setup to run 2, 250w HQI pendants with 4, T5 bulbs. How high should I run the pendants above the water? When I ran Moguls, I ran them at 10" above the water.

07/16/2007, 07:53 PM	#3
reefworm Registered Member Join Date: May 2000 Location: Waxhaw, NC USA Posts: 2,139	I agree - from a heat standpoint 250w 8.5"-9" over an open top can be handled by one 4" cooling fan blowing over the water. Temp rise after 12 hours only 1.5~2 degrees. I know that's too much, but right now I'm just testing the heat issue. 6-7 hours appears to be a consensus on appropriate amount of light. __________________ "The best argument against democracy is a five-minute conversation with the average voter." - Thomas Jefferson Current Tank Info: 29 gal. reef/assist with 75 gal. at the school

07/16/2007, 09:43 PM	#5
reefworm Registered Member Join Date: May 2000 Location: Waxhaw, NC USA Posts: 2,139	correct. 6-7 hours for the most intense light overlapped with other light sources such as those you mention. I plan to run the T5 actinics about 10 hours. Apparently more than those hours of MH is too much intensity, kinda like noonday sun for most of the day. __________________ "The best argument against democracy is a five-minute conversation with the average voter." - Thomas Jefferson Current Tank Info: 29 gal. reef/assist with 75 gal. at the school

07/16/2007, 05:35 PM	#2
reefingagain Registered Member Join Date: Mar 2002 Location: CA Posts: 505	10" is safe most ppl have it between 7-11" Make sure to acclimate your corals since there use to t-5's you can start with a 4hr photo period and increase 1 hr per week or have the pendant high and slowly bring it down or a combination of the two.