How Long Should I Backwash My Pool?

Backwashing your pool weekly is essential for keeping your sand filter clean from contaminants and working properly. This will help keep your pool nice and clean. But how long should you be backwashing your pool for?

You should backwash your pool for 3 to 5 minutes or until the water runs clear. You should never backwash for more than 5 minutes at a time unless your pool is abnormally dirty. Backwashing for too long can remove particles that actually help filter the water more efficiently.

Rather than just backwashing your pool for long periods, you need to make sure you are backwashing your pool often enough instead. You don’t want to backwash your pool too much either.

Too much dirt in your filter will put a lot of strain on your system and too little will have an adverse effect on your filter’s ability to clean the water properly.

How Often Should I Backwash My Pool?

The filtration system is the heart of your pool. It can mean the difference between a clean, and pleasant swimming experience, or an algae infested cesspool. So having a regular backwashing schedule is very important in keeping your filter clean.

You should backwash your pool at least once a week. If your pool has recently been contaminated with mud, there will be additional strain on your filter and you should backwash it daily until your pool is clean. You will also want to backwash your pool immediately after vacuuming it.

If you notice that the pressure in your system is increasing and you can hear the pump straining, then it probably means that your filter is clogged and needs to be back-washed.

How To Backwash Your Pool [My recommended routine]

As mentioned before, you should try to get into a regular schedule of backwashing your pool. Choose one day in the week for backwashing your pool. This might be on a Saturday morning for example, while you soak up the sun with a cup of coffee.

1. Clean the skimmer, hose, and pool cleaner.
First things first, you want to clean your skimmer basket to make sure your pool cleaner is clear of leaves or branches and is operating. This is necessary so that the pump can pull water from the skimmer easily without obstructions.

2. Turn off the pump.
NEVER move the valve lever while the pool is running, this could damage the mechanism and you will have to replace it. You should also only ever rotate the lever in a clockwise direction. Moving it both ways can also damage the mechanism.

3. Set the filter to the Backwash setting.
Move the lever from the filtration setting, in a clockwise direction to the backwash setting. Now make sure the backwash hose is either discharged into a drain, onto the street (if that is allowed in your area) or onto a part of your garden that is clear of buildings well away from your pool.

You should also make sure that you are not dumping water into your neighbor’s property that could end up damaging any foundations etc.

Never discharge the pool water into a lake or stream as the chlorine and other chemicals can kill important micro-organisms in natural wetlands.

4. Turn on the pump and start your timer.
The first few minutes of backwash water may be brownish and cloudy, this is normal. Leave the backwash to continue for 3 minutes. If the water is clear after 3 minutes, then you can turn off the pump. If the water is still cloudy, allow the backwash to proceed until the 5-minute mark and then turn off the pump.

5. Turn off the pump again

6. Rotate the lever to the rinse setting.
Next, you want to run the pump with the valve on the “rinse” setting for 30 to 45 seconds. This prevents any leftover dirty water inside the system to be flushed so that it doesn’t end up back in the pool.

7. Turn off your pump… Again.

6. Now set your valve back to filtration setting, turn the pump on again, and you’re done.

By the way. Depending on your water level and how much water was used o backwash your pool, you may need to raise your water level if it is below the skimmer. Allowing your water level to drop below the skimmer opening will cause the system to draw air into the pump. This could end up leaving your pump running dry and potentially destroying it.

Read What Happens If My Pool Pump Runs Dry?

Finish your coffee and enjoy the rest of your Saturday.


Backwashing your pool is not something you should be neglecting. It keeps your pool filter nice and clean, which reduced the load on your pool pump and increases its longevity.

Try to make the backwashing routine a habit by doing it regularly on a weekly basis.

Before moving the filter lever between settings, only ever move the lever in a clockwise direction and when the pump is turned off. Moving the level the wrong way, or while the pump is running can cause damage to the mechanism leading to expensive repairs.

You need to make sure you’re not backwashing for too long, or not long enough. You want to keep your backwashing length between 3 and 5 minutes. The backwash water should be clear when before you finish the backwash.

It is also important to rinse the system after the backwash so that the dirty water in the valve doesn’t end up back in your pool.

Backwashing removes water from your pool, so be sure to check your water level after each backwash. If the water level is lower than the skimmer opening, you will need to top it up.

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