Thanks for the quick responses. I appreciate the information on the better quality cartridge filters. I really do want to increase the size of the pump to do a better job of moving the water around the pool. I could get a higher volume pump that utilizes cartridge filters, but I figured that if I were to upgrade the pump, the sand filters would require much less upkeep. Do you think the cartridge filter would be a better option? Whichever way I go, is there a downside to having a pump with twice the volume of the one that came with the pool?