The effect of the filter is mechanical biological and with uv radiation together with a pump order no 57 21 93 or 57 21 94 it provides a compact and complete filtration system dar the pressurized water can dine under the spout waterfall and provide better oxygenation to your pond besides the fast cleaning system the device is in the open for providing easy maintenance without the filter through the resulting vacuum pressure the pond filter is cleaned completely the maximum flow rate