Its just a powerhead in one tank with a tube that goes to the other tank on the output. If it quits the water movement through the pvc will stop, but wont hurt anything as long as I replace the pump within a reasonable time frame. The water flow is just to keep the water in the pvc fresh, so the fish like it more. It also allows the fish to know if I put treats in the tank they are not in, by smelling the water coming though the pvc or the tube.
