Backwashing A Hayward Sand Filter

1. Your filter pressure gauge should normally read between 10-15 psi if the pool water is clear.  If the pool water is not crystal clear expect the filter pressure to rise, even in a matter of hours.  The water is being cleaned by the filter; it will clean the pool if you clean it!
2. As the sand in the filter collects the particles in the water the pressure will start to build.  You will notice the water will move slower and slower going back into the pool.  Once the pressure gauge reads 8-10 above the normal psi (ex. If your regular pressure is 12 psi and you’ve reached 20-22 psi) it’s time to start the process.
3. Locate the large valve screwed to the side of the filter tank.  This multi-port valve (called this because of its multiple ports for water flow) has two positions that we will use in the cleaning process: backwash and rinse.
4. Turn the electricity to the system off.  Push down on the multi-port valve handle and pivot towards the backwash position (there is a notch the valve handle must sit in). You must press the handle down all the way or risk damaging the valve.
5. Turn electricity back on.  Water flushes through the dirty sand and out of a waste line.  You can see the condition of this water by looking at the sight glass on the side of the valve.  Run the system approximately 30 seconds or until water in site glass is milky but no longer brown/green.  
6.  Turn power off.  Turn valve handle to the rinse position.  The pool must never be running when you switch valve positions, you will break the valve.  Turn power back on.  Run system for approximately 5 seconds or until water in site glass is clear.
7. Repeat steps #4, #5 and #6 five to seven times (yay!).
8. This will clean the filter sand of all debris.  Once you have gone through the last rinse cycle, move valve handle back to the filter position.  Turn the power back on.
9. There will be times where the sand will be unable to trap super-fine particles.  If your filter is not clearing the pool water completely, please bring a water sample in to check you water chemistry. Also to discuss filtering aides and the need to possibly replace old sand with a new batch.