I am very happy with it the means, it works exactly like it says on the description. I would every pond owner emfpehlen this means the four weeks, the algae were almost completely wiped out after it dauerete only noche almost a week all filamentous algae Rester were eliminated. The UV lamp in the filter I have not re-use it also recommends not the bacteria die with the UV lamp and gives a good breeding ground for thread algae and floating algae.
