What Is Backwashing A Pool?

If you own a swimming pool, then you will know that regular maintenance is one of the best ways to keep it looking super clean and safe for the whole family, and those friends who like to visit.

Whilst backwashing can be done by a professional, it is also easy enough to do yourself. This not only makes the process inexpensive, but it means you can perform the task yourself when it is necessary to do so without having to call someone up.

If you are a little unsure what it means, or you are wanting to know how to do it, then you have come to the right place. So, let us take a look at backwashing in more detail.

Why Backwash?

Sand Filters are a common part of a swimming pool, and they work by trapping debris that finds its way into the water. The bits of dirt buildup within the sand grains, and in doing so block the filter.

This means the filter is not working as well as it should be, and the swimming pool is not being cleaned of dirt.

Due to this, water can pass through without being filtered, and this in turn will allow bacteria to take over the pool’s water and potentially cause the swimming pool to become unhealthy.

This also means you could become sick just by swimming. To stop this from happening, backwashing helps to get rid of the buildup and lets filtered water run freely into your pool.

What Is the Process of Backwashing?

Backwashing is the process in which a pool’s filter is cleaned via a method of backwash, rather than manually. It is a much faster way to do it, with the time only taking a few minutes to complete if done correctly.

It involves reversing the flow of water to help get rid of any bacteria, debris and dangerous hidden germs that can find its way into the filter. 

To know if the process is finished doing its job, all you have to look out for is clear running water making its way through the waste line or hose, depending on your set-up. Plus, the pressure gauge will have lowered, allowing water to flow through easily.

How Do You Know It Is Time To Backwash?

One of the main ways to check to see if your swimming pool needs a backwash is by looking at the pressure gauge. If it is numbered between 8-10 PSI (pounds per square inch) over the starting level, then it is time to clean the filter.

This means that if your original PSI number is 10, and it says 20, then a backwash needs to happen in order to clean the pool properly. 

How Often To Backwash A Swimming Pool

To keep on top of regular maintenance, it is advised to backwash a swimming pool once a week. This can be done once other jobs have been completed, such as the vacuuming and regular clean.

That being said, there are circumstances in which backwashing should happen more often, such as if the pool is surrounded by lots of shrubs, what kind of filtration system it is, or depending on how often you use the pool.

It might seem like yet another thing to add to the growing list of things to do, but owning a pool is no easy task.

There are a lot of chores to do in order to keep a pool looking its best, as well as toxic-free for everyone to enjoy - especially during the warmer months. 

How To Perform A Backwash

Whilst backwashing is similar no matter the filter type, it is always worth looking at any instructions from the manufacturer in case something does not work. Here is how to backwash a general filter:

1. Once you have turned off the pump in order to make the process safe, it is time to take a look at the different settings on the multiport. If there is a ‘backwash’ setting, then use that, otherwise you may find that there is a ‘pull/push’ handle. In this case, use the opposite way to what it is currently set at to make the water go through as a backwash. 

2. You will want to make sure all of the valves for the backwash line are open, and then turn the multi-port to ‘backwash’ or turn it 180 degrees if it is the ‘push/pull’ setting.

3. Turn on the pump. To know it is working, you will see the water start to flow through the backwash hose. Keep this running until the glass runs clear. It will only take a few minutes to do.

4. Turn off the pump, and set the multiport to ‘rinse’ if it has the option available to you. Let it rinse for around 30 seconds and then turn the pump off. If this is not a step you can do, skip ahead.

5. Make sure all the valves are back to their original positions and move the multiport back to ‘filter’. If it was a handle for ‘push/pull’, then turn it back 180 degrees to where it was when you began the process.

6. Once all this has been done, turn the pump back on and everything should be working as normal. If the pool water needs to be filled up, then now is the time to do so. 

How To Backwash Using A DE Filter

 A DE filter is a little different, so here is how to backwash successfully:

  1. To make the process safe, turn off the pump and the filtration system.
  1. On the multiport, turn the filter value to ‘backwash’ and turn the pump back on. You will see the water flow through the glass, so you will know if it is working or not. 
  1. It is time to wait for the water to appear clear, but this should only take a few moments. Once this has taken place, you can stop the backwash process and use ‘rinse’ instead for about a minute.
  1. Once it has been turned off, dissemble the filter and throw the DE into the trash. 
  1. You will also need to drain the filter by opening the release valve and letting the water through.

When Not To Backwash

Backwashing is necessary, but it can also be a nuisance, and not just because it takes a bit of effort. It also removes water from the pool, which means every time you backwash you will have to top up the water and reheat it. 

There are also times when you should not backwash. These are:

  • If an algae outbreak has happened, then instead of backwashing you should vacuum the waste instead. The algae has a habit of bypassing the filter entirely and re-entering the pool’s water.
  • If for some reason there is a higher level than normal of debris, then again it is advised to vacuum the dirt instead of backwashing. This could be because of outdoor work, or a storm has passed through.

Final Words

Backwashing might sound terrible, but it is a great way to clean the filter that helps to keep the swimming pool’s water from becoming contaminated.

It only takes a few minutes of your time, and is extremely effective at removing debris that collects in the water. 

Whilst owning a pool does mean that there is extra maintenance involved when it comes to weekly chores, it is always worth it once you dive into the water on a warm afternoon.