How Often Should You Backwash Your Pool?

How Often Should You Backwash Your Pool?

When using the pool, backwashing is inevitable, the best you can do is backwash once a week. The term ‘Backwash’ is used to describe the filter cleaning process that reverses water flow via the filter system. That is, backwashing is sending water backward via the filter and then sending it out towards the waste/drain port.

The general rule is to backwash a swimming pool once a week. But the industry standard is for it to be backwashed when the filter’s pressure gauge is 8-10psi over the clean pressure or the starting.

The motive behind this article is to learn how often you should backwash your pool. Therefore, you are eligible enough to be explained, what backwash is. What is it then? It’s the system by which you clean your filter through the filter system (washing your filter) which reverses the flow of water inside the filter and then out in the waste/drain port. This washing off of your filter gets rid of organic materials and directs the water to a porous medium like sand and then take clean water back to the pool.

In this article, you will also learn how to get rid of the materials or unwanted particles that build up in the filter over time. It’s important to learn this because these particles increase pressure in the filter and then reduce its efficiency and effectiveness. When you backwash your pool frequently, you dislodge the unwanted particles, debris, or contaminants, then push them into the hose through a pool pump or a waste line.

How often should you backwash your pool?

To backwash your pool and how often to do it all depends on your pool’s filtration system or matrix and on how frequently you make use of your pool. Pool experts will also be of great help when you consult them. It may interest you that there is no strict rule concerning the backwashing of your pool. This is because filter differs; therefore the frequency depends on how often you use your pool and the type of filter you use also.

For example, the Polymer cartridge filter is different from the Sand/Glass microbead depth filter and requires backflushing/backwashing more often. They are mostly seen in smaller pools only. Also, the location of your pool determines how often you should backwash your pool. For example, a pool that has no pool cover and is located in a place where debris, particles, and or contaminants can infiltrate the water needs more attention and backwashing than the one sited in a location free from contaminants and or one away from bushes and trees and one also covered by an impermeable cover when it’s not in use.

Environmental factors also affect the frequency of pool backflushing – it is recommended to backwash in summer every four (4) to six (6) weeks and yet it is based on the pool water’s sensor reading through the filter and frequency of use. Sand/Media filters might filter best yet becomes slightly dirty in the process and later moderately. But when its filter gets moderately dirty, the gap between the sand grains gets smaller and surprisingly performs better but not until it clogs up finally. When it clogs finally, backwashing comes to mind.

Why would you backwash your pool?

Many without prior knowledge about backwashing or new to pool ownership and management may not know why they need backwashing. Well, as you wash your dishes after a meal, you do the same for your pool. The only difference is, you wash your dishes almost every day but wash your pool either once or twice a week considering all the factors mentioned above.

Why backwash? You backwash because when water passes through the diatomaceous earth – D.E or sand filter, it leaves both oil, dirt, and other debris which have been collected in the filter medium. As you use your filter regularly, water continues to pass in it in one direction. This makes it possible for the filter medium to get clogged and affects the effectiveness of the filter.

Backwashing helps you to send water backward via the filter and then out towards the waste or drain port. The process helps to take away the unwanted contaminants and particles and gets the water filter back to its effectiveness

There are several steps to take to backwash your pool especially the above-ground pool, and they are:

  1. Turn the pool pump off.
  2. Turn valve to the backwash position.
  3. Turn backwash valve on. Let the water pass through the hose for 2 or 3 minutes or when the water that comes out is clear. It gets rid of organic matter in the filter.
  4. Turn pump off.
  5. Turn filter valve on rinse.
  6. Turn the water on then rinse up to one minute – this is to compact the sands in the filter once again as the backwash turns it up.
  7. Turn off the pump, then reset the filter valve.
  8. Then turn the pump back on.

The above steps should be repeated at least once a week to ensure that the pool water stays pristine, clean, and inviting for swimming. Thus, regular backwash at this rate is recommended so that the effectiveness of the filter would not diminish because the pumps once get stuck up with debris don’t filter very well and their lifespan is shortened. Therefore, it’s best to do weekly pool maintenance to do away with dirt and stains.

Sometimes cleaning the pool with a vacuum is a good way to cleanse the dirt and unwanted debris from the pool. Let’s analyze the steps to vacuum your pool.

How to Vacuum your Pool

Regular vacuuming of the pool tends to extend the lifespan of the filter and keep the pool clean. Vacuuming the pool should be done regularly. You can vacuum your pool with the following steps:

  1. Set pool filter to rinse.
  2. Fill the hose (vacuum hose) with water, then attach it to a vacuum plate or skimmer disk.
  3. Keep it directly on the top of the suction vent.
  4. Move the vacuum head along the pool bottom slowly.

When you are vacuuming, try to take or suck up all debris you can see. When you move the vacuum, contaminants are moved through the vacuum plate and then into the pump – the debris passes through the sand filter, and the water is cleaned. After the vacuum, the next step should be to backwash the sand filter to be sure of the cleanliness of the filter so that it wouldn’t lose its effectiveness when functioning.

How do you know you need a backwash?

Before this, I have explained how to backwash, which is the reverse of the flow of water to wash your filter. It makes your filter dislodge contaminants and debris that are trapped and need to be flushed out through the multiport valve waste line. This backwash process has been also explained. Now let’s look at ways to find out that you need to backwash.

The steps are not far fetched but quite simple – they are:

  • Water Clarity – When you notice a change in your water or a kind of density, it indicates a dirty filter that is unable to filter properly or one losing its efficiency and effectiveness which has become weak and unable to get hold of contaminants or debris that is making way to your pool
  • Water flow – this is a very clear sign that your filter is slowly losing or has lost its effectiveness. When you notice the flow of water into your pool is reducing or has reduced, it shows that dirt, debris, or contaminants have been stuck or clogged in the filter media. Debris and unwanted particles clog the filter and reduce the rate of water flow into the pool.
  • Water pressure – this is when there is an increase in the psi reading (Per Square Inch). The psi should be regulated or normalized; the increase indicates either a blockage by debris and other contaminants, a strained pool, or faulty equipment.

The three factors above are the best ways to find out when your pool needs to be back-washed. But all the same, pay close attention to your pool as you may need to backwash it at least once a week to maintain the cleanliness and pristine nature of the water so it is ever inviting for a swim.

There are also some ways or steps to backwash using a sand filter and a DE, but first of all, I’ll outline the steps for backwashing using a sand filter. If you wish to backwash with sand filter, follow these steps;

  1. Go to the ‘pool maintenance‘ page.
  2. Press ‘guided backwash’.
  3. Press ‘start’ once you are ready to continue.
  4. Equipment stops running automatically.
  5. Press ‘next’.
  6. Press ‘next’ after you clean the strainer.
  7. Click ‘next’ after rotating the main valve that is on top of the filter from ‘filter’ to ‘backwash’.
  8. Start two (2) minute run on filter pump by clicking on ‘start filter pump’.
  9. Click ‘next’ immediately the filter pump stops.
  10. Now turn the main valve that is on top of the filter from ‘backwash’ to ‘rinse’, then click on ‘next’.
  11. Now its time for one (1) minute run for the filter pump, click on ‘start filter pump’.
  12. Click next once the filter pump stops.
  13. Now click on ‘resume normal operation’.
  14. Press ‘home’.

The process as a whole might be long but it’s the best way to effectively use the sand filter. The mastery of these steps improves with time and constant or frequent use. This is because the sand filter has a sweet spot from where they perform very well or rather, best. And surprisingly, it’s also when they are from slightly dirty to moderately dirty that the filter performs effectively until the filter finally clogs up and may need a backwash.

Having talked about how to backwash using a sand filter, let’s talk about backwashing using a Diatomaceous Earth, i.e, D.E.

A Diatomaceous Earth (D.E) is the type of filter that uses the D.E to catch contaminants and debris instead of using sand. Many people insist that D.E is much better in backwashing than the sand filter and that it does a better job in the filtering of pool water. But at the same time, it doesn’t come easy without extra maintenance. The backwashing of a sand filter is the same as the backwashing of a D.E filter but D.E is one step ahead (topping up the D.E).

Some steps need to be taken while washing or backwashing using the D.E filter. The steps are;

  1. Switch the pool pump off.
  2. Select ‘backwash’ on the filter valve.
  3. Turn the pool pump on again, then backwash for two minutes or until the water becomes clear – which you can always check in the sight glass on the filter side.
  4. Turn off the pump.
  5. Select ‘rinse setting’ on the filter valve.
  6. Turn pump on again and rinse for 1-2 minutes. Then repeat the steps 2 to 6 times (that’s when you notice that the filter is very dirty).
  7. Turn off the pump and select ‘filter’.
  8. Add the diatomaceous earth (D.E). while adding the D.E, you may need to:
    • Check the manufacturer’s instruction to know how much D.E you need to put
    • Add the diatomaceous earth (D.E) to the skimmer but mix it with water first and add some more D.E powder in the pump strainer while the rest goes into the skimmer. Also, check the manufacturer’s instruction after then.
    • For thirty (30) minutes or more, run the pump on the ‘filter’ setting to allow the diatomaceous earth (D.E) to coat the filler grids.


The frequency of backwashing which is at least once a week is one of the tips to pool maintenance. It all depends on the frequency of use and also the site of the pool. Backwashing is a tool that ought to be adopted by all pool owners.

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