Jebao PU Range UV Clarifier - 7w/9w/11w/18w/36w/55w. Jebao Pond UV Steriliser Unit. The water must be pumped through the unit and not gravity fed. The algae, causing green water, are made to clump together (flocculate) by the UV (ultra violet) light so that they can be sieved out of the water by a filter to give clear water.
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