Initially, less than when leaves and other organics start to accumulate. Perhaps a small system that would supply .75 to 1 turns per day would be adequate to run at night only from April-May timeframe to start in the spring thru October. You may want a winter aeration option also. At some point you will want to be able to run 24/7 for at least those same months in your situation.Plan on an amp draw (115volt) of 3.3 to 4.4 range. Consider also that 1/4 mile airline of 1.5 ID will also get the job done with the same small compressor. 1.5 inch airline only carries .00144 PSI per ft backpressure.Hope this helps.