Solves algae problems by removing the algae nutrient phosphate from the aquarium water. Just insert the filter cartridge into the filter basket of the JBL internal filter (CristalProfi i 60, 80, 100, 200) instead of the filter sponge. Completely ready for use with inner pipe. Can be refilled with JBL PhosEx ultra if required. Replace after 2-3 months or check phosphate content with JBL phosphate test and use new filter insert if phosphate level has risen again (or refill with JBL PhosEx ultra). Package contents: 1 filter insert with 190 ml PhosEx ultra phosphate remover for 50 100 l