no water pump... It uses air pump to circulate res. Its called a venturi pump
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see that thing in the middle.. you hook a air line to it. Air pushed down and makes water come up the tube and circulates it...
Its called the
WaterFarm recirculating kit.. Even comes with a junk air pump
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That is everything that comes in the kit.. enough stuff to convert 4 single dwc buckets to a recirculating system, the cheap way. $50 and I grew out 2# with it so its a proven winner...