danmalette

I was having this same problem (but thankfully, my filter didn't crack like yours). I purchased a second filter so that I could always have a clean one handy and change/clean them more often. I now rinse one a week, soak in TSP once every two weeks, and soak in spa filter cleaner once every 4-6 weeks. I may try soaking in muriatic acid at some point too. Also, as a newbie myself, I struggled with water sanitization for a while which probably put added pressure on the filter. As I got better at it, and as I cleaned the filters more often, the problem of the collapsing filter hasn't happened lately. I suspect that this is a known issue. I noticed that Hydropool recently changed the product number for these filters (from to 4520034 to 4520035). Maybe they (or the filter manufacturer) have redesigned the filter somehow to deal with this issue. These filters seem to be in short supply right now though. Hope that this helps a bit.