Here is a clear explanation and example of an Aquaponics trouble free automatic syphon or bell siphon for flood and drain beds. The key to having healthy vegetables in your flood and drain bed is having a good working siphoning system to ensure your plants get plenty of oxygen and moisture. This example uses clear PVC pipe and a clear grow bed to make it easy to see and understand the working components. Clear PVC is not needed in your aquaponics system; it was used here just for demonstration purposes for this video. Aquaponics Online Workshop http://growdinner.com/grow-dinner-aquaponics/aquaponics-workshops/