With Dave Weldon's advise, I have just set up my system for 6 cages. When I went to cut the threads on the inside of each end of the Hydor 300 watt heater, I discovered there is a difference between METAL PIPE Tap threads and plastic tap threads. Be sure to get the right one.
The white plastic fittings are found at Lowes or Home Depot in the refrigerator section, they use them to plumb the water to the refrigerators for ice makers and water in the door.
You only want your water heated just prior to, and during misting, as standing warm water will breed more nasties to mess up your Chams eyes, etc.
The hottest water out of your tap will be cool enough for the Chams, because as it sprays out it looses a LOT of heat. Fire that 300 watts up! (try spraying your hottest tap water on your arm through a hand mister-it really is true!)
Dave Weldon talked to me about the challenge of not dousing your Chams with the room temperature (aka COLD) water that is in the 1/4 inch tube and supply bucket, in the beginning of the cycle. So... I am trying something "outside the box."
I am using a continous system that does not "dead end," but dumps back into the supply bucket. The pump and heater run PRIOR to misting to warm all the water in the tubing, as well as the supply bucket. Then a selenoid closes the system as it dumps into the supply bucket and that creates the pressure to fire up the nozzles. So far I have great results, but more time is needed to record temperatures, and verify that the system has no weaknesses.
Hope this helps!!
CHEERS!!!