This will be the first time closing for me. I'll be using a Cyclone II Blower for this. I will be disconnecting the pump and blowing air directly into the PVC pipes. My plan is to bypass the sand filter by setting the valve to the "re-circulate" position prior to blowing the returns and the heater. My thinking on this is that it will lessen the possibility of blowing sand into the heater.
My question is...Is this a legitimate concern? getting sand in the heater? Or would it be better to set the valve to "Filter" thereby including the filter in the loop while blowing the lines? Is there anything to be gained by blowing air into the filter? I HAD been under impression that leaving the air relief and drain caps open for a few days would be enough to drain ALL the water out of the filter.