How to backwash a filter
Cleaning your filter regularly is a key component to keeping your pool clean. If the filter gets too full it will reduce water flow, slowing the removal of dirt, dead bacteria and other debris large or small. It can also prevent automatic chemical dispensers or chlorinators from dosing your pool water. If left too long this can create other problems such as a green or cloudy pool or even damage your equipment.
In most cases the cleaning of a filter is quite simple. However, for sand or media filters it can get a little difficult to remember the correct procedure, so we have provided the following guide to backwashing a filter.
Be sure to read through the full instructions and the 'Things to consider' section below before attempting this procedure.
Disclaimer: These instructions are intended as a guide only and do not take into account all situations. For instructions tailored to your pool we recommend booking a handover service with Pool Geeks Brisbane or your local pool service provider.
Things to consider
Check for any valves in the waste line. If there is a valve in the waste line ensure that it is in the open position before performing a backwash or reducing the pool water level and close it again when finished.
We highly recommend keeping other equipment switched off whilst you perform the backwash, particularly chlorinators. If the chlorinator continues to send electricity through the cell without water flow this can cause a potentially dangerous build up of gas or damage the cell. Many new chlorinators have a built in function that allows you to backwash the filter safely. Check your chlorinator manual for details.
As a rule of thumb, most filters should be cleaned once a month. However, many factors, such as the size of your filter and the amount of debris that enters your pool can influence how often you should clean it. Regularly check your pressure gauge and if the pressure increases by more than 20kPa you should consider performing a backwash.
Backwashing your filter will use a fair amount of water. Make sure your pool water level is at least half way up the mouth of the skimmer box. We recommend maintaining your pool level to 3/4 of the way up the skimmer mouth.
In most cases the pump draws all water from the skimmer box in the side of your pool. If the water level gets too low the pump will start to suck air. This can cause the pump to overheat, melting internal parts and voiding your warranty.
How to perform a backwash:
DO NOT perform the following until you have read through the 'Things to Consider' section.
1. Switch off the pump
2. Press down the handle on the multi port valve (MPV) and twist to the ‘Backwash' position. Release handle.
3. Turn pump on (if possible avoid turning other equipment on with the pump). Run for 2-3 minutes or until water in eyeglass becomes clear
4. Turn off pump
5. Press down handle on MPV and twist to ‘Rinse’ position
6. Run pump for up to 1 minute or until water in eyeglass becomes clear
7. Turn off pump
8. Press down handle and rotate to ‘Filter’ position
9. Return pump and chlorinator to normal settings
To reduce water level after heavy rain
DO NOT perform the following until you have read through the 'Things to Consider' section.
1. Switch off the pump
2. Press down the handle on the multi port valve (MPV) and twist to the ‘Waste' position. Release handle.
3. Turn pump on (if possible avoid turning other equipment on with the pump). Run until water reaches the desired level.
4. Turn off pump
5. Press down handle and rotate to ‘Filter’ position
6. Return pump and chlorinator to normal settings
