The Tilapia that I am raising like warm water. They grow fastest in water that is 80 degrees. The nice thing about that is that the grow beds that the water goes through is nice and warm and along with the high nutrient level of the water because of the fish poop, the plants that I am growing in the greenhouse are growing like crazy. Heating the water has been the biggest expense of raising Tilapia in my aqaponics system. Today I took 70 feet of 3/8 cooper tubing and rapped it around and around the stove pipe on my wood stove and plumbed it into two pec lines that I had running to my greenhouse that are insulated and buried. Got everything hooked up and turned on the pump and it all worked like a charm. The water coming out into the tank where the fish are is about 90-95 degrees. I think I will take care of most of the heating expense with this plan. It is always fun to have a problem and then to invent a solution for the problem that works. We were created by God in His image and likeness. The proneness that all of is have to create, to invent, to solve problems comes from God, and is a lot of fun. I wonder what I will create tomorrow.?