Dirt particles that are lighter than water (e.g. pollen & dust) settle on the water surface as a floating layer. This floating layer is removed when the tank overflows by means of the overflow siphon in the tank. Also aids in mosquito prevention.
When used in conjunction with a Calming Inlet, the Overflow Siphon prevents mosquitoes by acting as a water trap where mosquitoes cannot enter or exit the tank.
Connects to standard 4" PVC using a Fernco fitting