These filter balls are the best thing I ever did for my pool!! I have well water and have had a terrible time cleaning my pool water until now!! Replacing the filter sand with these little jewels was a game changer! Now I don't have to backwash my filter near as much and when I have to add water these things filter the rusty red color out of my pool within an hour or two instead of a week! I won't ever use anything else. I was amazed at how much these could filter out and hold! They don't fall apart like other filter types. I have even replaced my fish tank filters with them and they work great! Definitely worth a try! Highly recommend!!