I have a Intex® Krystal Clear Sand Filter - 16" pump for my Intex 32 ft. x 16 ft. x 52 in. Rectangular Ultra Frame Pool. I purchased a Hayward AquaRay Automatic Pool Cleaner. It will run for a short period of time and then stop pumping. I take it off and the pump is just barely sucking. How can I improve the amount of suction into the pump. I checked for blockage and found nothing.