Anybody keep fish in tanks for food

[BFG Central]

Iv got Tilapi in a 4 ft fish tank in the kitchen at the moment.
They are going into an Aquaponics system later this year.
Tilapia are the third largest farmed fish behind salmon and tuna world wide.
Yes they need to be kept in heated water as they are tropical fish but the plan is to build a rocket stove mass heater to heat the water.
The water acts as the thermal mass and the tank and grow beds are insulated.
Its my project for this Autumn.