Put a ball valve on the return line, when you start it up keep it wide open cus you will have head loss and if you add elbows more loss there. If the tank water rises to high then turn down the valve. Placing the weir of the overflow box properly is important but easy. It will adjust the height of the tank water to prevent flooding. Start off at just above the bottom of the tank rim.(black support around tank)adjust if needed. Good flow thru the box will keep the siphon and will start right up after you plug the pump back in after wc.