Agreed. Pick up any submersible pump with 1/2" threads, a piece of 1/2" pvc pipe, a 1/2" threaded male pvc adapter fitting, and 2 1/2" pvc 90 degree elbows. Depending on the height of your reservoir cut the pvc into 2 pieces of unequal length. Slip the threaded adapter on one end of the longer piece and a 90 degree bend on the other. Screw this into your pump. Slip the other 90 degree bend onto one end of the smaller piece of pvc and slide the free end into the 90 degree bend on the vertical pipe rising from your pump. Obviously the exact lengths of your pvc pipe would depend on your water level and inside dimensions of your reservoir. If done correctly the pump will suck in the water, shoot it up the vertical pipe through a corner, across the short horizontal pipe into another corner, and exit the second corner being shot downward through the air and back into your reservoir accomplishing both circulation and aeration. Hope this helps!