I appreciate all of your replies. I've been out of town and haven't been able to test for a week. However, my filter now seems to be staying cleaner. I'm on my second week of not cleaning it and my pressure is good and waterfall is working properly. Might have been the stuff the pool store guy was selling me that was clogging it. Eliminating the PhosTKO is the only big change I made. My water is crystal clear. Tested this morning and just needed a little tweak. Thank you everybody for all of your input!