When I built my current 100G with 30G sump system 9 years ago I installed 2x250w MH and 2x140w VHO with PFO parallel reflectors in a totally enclosed canopy. I drilled 4" holes in each end of the canopy for 120mm fans and drilled the same size holes in the roof of the canopy directly over the reflectors so heat would escape but light would not. I also had a 1/4HP SeaClear chiller.
I found by experimenting with the fans over the next couple of years tha the chiller wasn't needed, even in Phoenix in July and August with the home AC on a setback thermostat and the house warmer than normal. By placing two 120mm computer fans, one in each end, both blowing in, I could keep the tank at 78-80 year round. In fact when I started the fans were running at 12v on the same timer as the lights and the tank could actually get too cool and cause the heater to come on and evaporation went thru the roof. I later added a Ranco dual stage temperature controller and placed the fans on that so they ran as needed. I also put the fans on adjustable DC power supplies so I could slow them down in the winter months when cooling was not needed as much. Evaporation went way down.
I also had and still have a WalMart clip on fan over the sump as an emergency back up but sold the chiller two years ago after it never running for two years unless I ran it manually just to make sure it still worked.
In the last year I have sold the MH and VHO lights, the Ranco Controller and all the timers and outlet strips and replaced it with a ReefKeeper Lite controller and two AI Sol Blue LED fixtures. The two best investments I have made in this hobby. The fans are now controlled by the RKL and never come on. The LED lights could be on the controller but I really like their AI controller, it has so many adjustments its crazy. The tank stays at 78 degrees year round, my evaporation has gone way down and things are much more stable. Best of all I have cut my household electricity bills by over 30%!
I found by experimenting with the fans over the next couple of years tha the chiller wasn't needed, even in Phoenix in July and August with the home AC on a setback thermostat and the house warmer than normal. By placing two 120mm computer fans, one in each end, both blowing in, I could keep the tank at 78-80 year round. In fact when I started the fans were running at 12v on the same timer as the lights and the tank could actually get too cool and cause the heater to come on and evaporation went thru the roof. I later added a Ranco dual stage temperature controller and placed the fans on that so they ran as needed. I also put the fans on adjustable DC power supplies so I could slow them down in the winter months when cooling was not needed as much. Evaporation went way down.
I also had and still have a WalMart clip on fan over the sump as an emergency back up but sold the chiller two years ago after it never running for two years unless I ran it manually just to make sure it still worked.
In the last year I have sold the MH and VHO lights, the Ranco Controller and all the timers and outlet strips and replaced it with a ReefKeeper Lite controller and two AI Sol Blue LED fixtures. The two best investments I have made in this hobby. The fans are now controlled by the RKL and never come on. The LED lights could be on the controller but I really like their AI controller, it has so many adjustments its crazy. The tank stays at 78 degrees year round, my evaporation has gone way down and things are much more stable. Best of all I have cut my household electricity bills by over 30%!