[ChemE]

OK, lets do this thing.

Post a list of all your equipment that is adding heat to the tank as well as how long it runs per day. From this we can determine how much heat you need to reject to the Ti coil which is also how much heat your geothermal loop needs to reject to the ground. Both of which are very easily calculated (I'll post the calcs). I think you'll be surprised how little flow rate you need to make this happen.