Mike,
Are you keeping your water heated all the time? I am pretty new to this hobby as well, but I don't think the amount of energy used to heat 40 gallons and keep it heated is worth it. I used an old aquarium heater (150W) in a five gallon bucket to heat the water just before I do the WC. I takes about six or seven min to bring each 5g bucket up to about 75degrees.
Just my opinion..
~grace