Step 8: Test the Bell Siphon
To make sure everything works properly before adding rocks, set up the system for a quick test. Attach the long 1/2" PVC pipe to the discharge of the Bulkhead Fitting. This long discharge will help to keep the siphon going. Put the Bell over the standpipe.
Running pumps dry is bad. They use the water they pump to keep themselves cool. Put enough water in the bottom of the tank to cover the pump. Turn on the pump and make sure it pumps water into the Grow Bed. If not, you may need a bigger pump. Now that you know the pump works, Add more water to the tank and turn on the pump. Fill the grow bed, and look for leaks on the Bulkhead Fitting. Also check to make sure that the shelf isn't going to break. That would be bad. Once the water level gets above the standpipe, water will start flowing through this siphon. It will be slow at first, and then SLURP! speed up as the air is sucked out of the Bell. Make sure that when the Grow Bed is empty, the siphon action stops. If the pump is going too fast, it may be adding water just as fast as it is draining. If this happens, close the ball valve a bit. Mark the maximum level of the water.