The filter is the most important part of your system when it comes to ensuring the pool water remains clean and sanitized. There are three kinds of filters: diatomaceous earth (D.E.), cartridge, and sand. All three filters work to keep the water clean by removing small debris and fine particles.
If you notice a puddle around the filter, it may be leaking; it is often best to just replace it completely. If your filter is running in short cycles, the leak may be an indication of an excessively high flow rate. This means your filter is too small or your pump is too powerful. If you notice dirt particles on the floor of the pool after backwashing, it could be a sign that there is a faulty part, and again a replacement filter is recommended.