Normal filtration operation of George is shown schematically in Figure 1.

The pump motor sucks water from the swimming pool through the flap valve. The flap valve is forced open by the water. The water is sucked through the leave trap, through the motor impeller, from where it is pushed through a sand filter.

 

From the filter, the water is pumped into a pressure vessel where the force of the water causes air in the vessel to compress. An outlet pipe of the pressure vessel is connected to a backpressure valve which is adjusted to determine the pressure in the pressure vessel. Water flows past the backpressure valve back into the pool.

Backwash operation of George is shown in Figure 2.

The pump motor is switched off, causing an initial slight pressure drop in the pressure vessel. This pressure drop causes the backpressure valve to close. The compressed air now expands causing the water in the pressure vessel to flow in a reverse direction through the filter (thus backwashing the filter), through the impeller, through the leave trap basket (taking with it all leaves and debris collected in the basket), down the T-pipe and out through the duckbill valve into the filter bag. Note that the water flow causes the flap valve to automatically close so that water can only go down the T-pipe and not back into the pool.

The filter bag is located in the backwash water collector. All debris that was in the leave trap basket collects in the filter bag and the filter bag filters the finer particles from the water before the water exits the backwash water collector, under force of gravity, back to the return line and back to the pool.

From the above it is clear that George! backwashes every time it is switched off. The filter media and leave trap thus remains clean ensuring efficient operation of the system.

A timer can be connected to the pump motor electrical supply. The timing can be changed depending on how dirty the pool is.  For example, if the pool is dirty and full of leaves, short cycles, say, 2 hour cycles can be selected to remove leaves and other larger debris from the pool as well as backwash the sand filter every 2 hours. There is no need to manually clean a weir basket.  All the debris collects in the washable or replaceable filter bag much like a vacuum cleaner bag.  Every now and then, the filter bag may be emptied or replaced.