Hi-I've been using the TFP method for a few years and pool looks great. Lately I have sand by the jets. I had a pool guy out and he said I needed a new filter at the cost of $1,200-commercial grade-which seemed a little much. I went on you tube and it seems that my lateral assembly my be the problem. We also need a new O-Ring we were told. We have experience with changing the filter sand-which we did before we found this web site a few years ago, in an attempt to clear our water. So we feel pretty confident in our ability to change the lateral assembly. My question is, is it likely that it could be another issue instead of the lateral assembly? We had a new pump installed a couple years ago, so that part should be fine. Thanks for any advice.