10 microns allows very high filtration fineness. It filters fresh water whose external pollution is very low. You can use the 6 micron filter bag when the use of your swimming pool is relatively low. It retains impurities for clear clear water and thus provides perfectly crystal clear water. This bag requires regular maintenance and cleaning. 15 microns recommended in season under normal conditions of use of the swimming pool. It thus offers you balanced swimming pool water throughout the summer. Depending on how dirty the bag is you can simply clean it with a jet of water. 30 microns ideal at the start of the season for restarting your swimming pool and during wintering. It is also used for charged or unbalanced swimming pool water or for catching green water. This pocket requires less frequent maintenance and cleaning than other pockets. You can simply clean it with a jet of water or put it in a washing machine without cleaning products/detergent at 30C maximum