Metal Halide Heat
by
, 03-30-2010 at 07:39 PM (2392 Views)
I'm looking for advice and opinion on what amount of water temperature rise is acceptable during an 8 hour metal halide lighting period. I have two, 250 watt mh installed in an enclosed canopy on my 70 gallon reef. I'm using two 4.5 inch fans for cooling which do a pretty good job, but I see steady water temperature increase of about 2/10ths of a degree per hour when the MH are lit. I have my temp controller set to maintain water (heater) temp between 77 and 78 degree f. The conroller is set to shut the halide lights off at 78.4 degree. They stay off for an hour and then re-light. It takes about 4.5 to 5 hours for it to shut off the first time, and then about 2 to 3 hours to repeat the cycle. The 1.5 degree variation over the course of the day seems like it should be OK, but I don't know . Is there any rule of thumb or thoughts on this? Are the periods when the halides are off (actinic stay on) detrimental to my critters. Could I get away with a greater temp increase before I shut the halides off? I appreciate any and all comment.
Steve