Why cant you keep your 40 breeder under 82? how warm is your house during the day? My house is set to 82 during the day and with a fan over my sump the tank is fairly stable at 78 degrees. Do you have any type of active cooling, do you have a canopy or open top? As for the chiller, they are expensive plain and simple. Look at your local clubs and try and find one used is your best bet. Dont try and skimp and buy one two small for your system, as it will be running constantly and any money you saved up front you will soon pay and more to PG&E.