It can be a bit hard to tell if it is time to change your pool filter sand. One of the best ways to know that the pool and needs to be replaced is simply knowing the last time that you replaced it. If it has been several years, chances are it is time to replace the filter sand. Another way that you will sometimes know that it is time for a replacement is that the pool will be much harder to keep clean. You may notice that you are using more chemicals or having to backwash more and more. This will probably happen gradually, but it is something that is worth paying attention to. Another issue that people notice is that the pool water chemistry becomes difficult to balance. Luckily the new sand should make it easy to get your pool back up and functioning.