With EHEIM LOOPpro we offer you unique conditions for crystal clear and healthy water in your garden pond. LOOPpro is the optimal filter for your garden pond, because it offers unusual advantages: It is the only one with a pre-filter based on the pre-filtration principle of EHEIM external filters. The circulation pump installed in your pond brings the water to your filter which arrives through the UVC to eliminate germs, spores of harmful algae in the direction of the pre-filter to keep the larger impurities that will be captured, then the water will go down to the separate filter foams before going back up to a level fed with bioballs for a discharge to your pond of a healthy and oxygenated crystal water.