Oase compact drum for gravity fed ponds . An excellent drum and moving bed combination , in one easy plug and play filter ! Gravity fed in , pumped out , all connections via 4" rubber connectors . Internal pressure pump ( 4 bar ) so no plumbing for the cleaning pump . No wiring except three pin plug . Comes with media and a 63mm valve at the bottom to allow the unit to be emptied . The unit has full programmable control unit , which will even tell you how many times the unit is cleaning . Auto cut off , when the lid is removed for safety !This has to be one of the best small drums on the market ! We recommend , that when fitting , a flush valve before the unit is added , so that the drain can be flushed , and the screens cleaned twice a year in oase pump cleaning fluid over night . PLEASE WATCH THE VIDEO BELOW .

On this model , water enters the drum through the 4 " inlet . It is then "sieved " through the drum , and enters the clean chamber , where the cleaning pump is situated . When the drum becomes blocked , the water in this chamber lowers , the sensor in this chamber senses the drop  , and starts to revolve the drum , and in turn starts the water pump which delivers water to the jets and cleans the screen of the drum . The waste water is collected inside the drum by a hopper , which then leaves the filter on another 4" pipe .When the drum is clean enough , so that the water level returns to its normal level , the sensor turns of the whole process .  Please note , we recommend that this stays 4" all the way to the drain , if reduced it can become clogged with leaves . blanket weed etc etc . Clean water then leaves this chamber , and enters the bio chamber , where it mixes with Oase hel-xmedia , that is constantly being moved around via the aerators situated at the bottom of the chamber . Please note an air pump of 40-60lpm is required ( not included )