I have use a cartridge filter with my 27' AG pool for 6 seasons now. I like it. It provides good filtering. I only need to clean the cartridge about once a month. It takes about 20 minutes to clean with a garden hose. At the end of the season, I clean the filter real good and store it in a box. This way I can bring my filter housing and pump into the garage and store it over the winter. A cartridge lasts me about 3-4 seasons. Years ago I had a sand filter with another pool and did not feel that the filtering was as good. So I am happy with my cartridge.