My first message here- thanks to you all for your time and expertise.

I have a heat pump that typically requires 3 to 8 gallons of water per minute. The well which supplies it produces 13 gpm via a 3/4 HP Goulds pump. The well pump runs whenever the heatpump runs, regardless of how much water the heatpump needs. (The system bypasses the little pressure tank whenever demand exceeds 1/2 gpm, if I understand correctly).

Unfortunately, the cost of operating that large pump motor is eating up a big part of the savings I realized by installing the heatpump! It appears the best solution would be to find a reliable way to fill an auxilliary tank of sufficient volume (150 gallons would be plenty)with the well pump and then have that water handy for the heapump to draw on as needed.

The design problem is that simple floats would turn on the well pump as soon as the water level dropped just a few inches; I need it to only come on when the tank is nearly empty. And, I need it to continue to run until the tank fills, regardless of what the heatpump is calling for. This would let each system operate at its optimum efficiency.

In trying to find information I ran across this forum. I'd be very grateful for any help.

Thanks in advance,