Steps for Backwashing a Pool Filter

Backwash your pool regularly to keep the water clear.

Backwashing is essential to keep your swimming pool filter working efficiently. Backwashing is a procedure that reverses the flow of water through the filter to clear any debris that may be trapped, preventing free flow of water. You should backwash sand and diatomaceous earth (DE) filters regularly. You don't need to backwash cartridge filters but you do need to clean them. Although the basic backwash procedure is the same for sand and DE filters, it may differ slightly for certain brands. Always read the manual before performing a new procedure.

Instructions

1. Locate the backwash valve. The push-pull valve, also known as a side valve, is a plunger on the side of the bulkhead of your filter equipment. Move the plunger up or down to open the flow of water into the filter or back it out of the filter. In DE filters, pulling the plunger up will usually cause the filter to backwash. In sand filters it is often the other way around -- push the plunger down to backwash the filter. Filters with multiport valves have a valve labeled "backwash."

2. Backwash every week. Add water to the pool if the level is down. Turn off the pump and open the backwash valve. Empty the leaf basket and replace it. Turn the pump on again and watch until the water coming out of the waste line is clear. This may take up to three minutes. On DE filters, backwash then run the water through the filter repeatedly for five minutes. Add more powder to DE filters when backwashing has been completed. If the pressure gauge goes up by more than 10 psi, backwash more frequently.

3. Use chemicals when backwashing is no longer effective. Buy the recommended filter cleaner at a pool supply store and pour into your sand filter following the manufacturer's directions. Remove DE filter grids and soak them in the appropriate chemical solution. Maintain the slide valve. You should lubricate the O rings once a year by removing the plunger and applying a lubricant. If the valve leaks, the gasket may have blown and you must replace the broken seal.

References

• Pool and Spa: How to Backwash a Pool Filter
• Expert Pool and Spa Inc: Backwashing Filters
• Pool Center: Pool Info