I have an IG plaster pool/spa w/ 2 hp single speed pump and 60 gallon DE filter. When I cycle from pool to pool, everything works great. When I suction from pool or spa and return to spa, I don't get good suction and my spa jets don't work. And, my heater works on pool to pool but from pool or spa to spa, it doesn't work. Pump works great, filter cleaned out. What do I do? Thanks!!