How To Backwash A Pool With A Cartridge Filter

Your pool filter is a very important accessory. It is very essential for the safe and efficient operation of your pool. It’s not only important just for maintaining the water quality of your pool. But it also plays an essential role in removing impurities and sediments, regulating the flow and distribution of water.

How To Backwash A Pool With A Cartridge Filter
How To Backwash A Pool With A Cartridge Filter

Why you should maintain your pool filter regularly

Many pool owners are aware that the filter is an important part of the overall pool system. However, they are not aware of how to take better care of it. Similarly, pool owners are often confused with what are the best supplies to keep the pool in perfect condition.

Why you should maintain your pool filter regularly
Why you should maintain your pool filter regularly

As mentioned, the filter purifies and regulates the water in your pool. If the water in your pool does not flow freely and does not distribute efficiently, it can lead to algae growth. Almost variably, this will result in stains forming inside your pool.

Asides from the stains and marks on the inside of your pool, a pool with stagnant water or impurities are not attractive to bathers.

Also, knowing how to clean the pool water filter is advantageous as your pool will be free of bacteria. Raw water brings impurities and particles that can make you sick if they lodge in your mucous membranes.

To talk about the maintenance of swimming pools is to talk about a large number of models and sizes. Also, each model has different filter systems. This is due to the capacity of the pool and the preference of the owner.

So, how do you take care of your pool filter? So as to understand better, we will let you know more about your pool filter, the tasks, necessity, and systems of cleaning. And finally, we’ll discuss how to clean and backwash pool filters generally. Also specifically, we will teach you how to backwash a pool with a cartridge filter.

Types of filters for swimming pools

Firstly, it’s vital knowing the various types of pool filters that there are in the industry. This is because there are various systems of cleaning different filters. There are various types – talk about the sand filter, diatomaceous earth (D. E.) filter or the cartridge filter. Each one is different, and they are often cleaned in different ways. Of course, their effectiveness varies according to what we need.

Types of filters for swimming pools
Types of filters for swimming pools

The three types of pool filters

Sand filter

The sand filters are the most popular and commercial because they require less maintenance. Certainly, this is an advantage. The fact that it uses sand to filter is ingenious because it goes the way of the natural system of the planet. The system consists of the water circulating through the sand inside the filter.

Read more: How do I know if my sand filter needs replacing?

Cartridge filter

These filters, as their name implies, consists of replaceable cartridges. However, they are easy to clean. A cartridge can last up to a year. However, that’s only if you do weekly maintenance. The cartridge composes of manufactured material; that is the basis of the filtration.

The diatomaceous filters

Diatoms are what scientists call fossilized microscopic beings or remains. The diatomaceous earth act as filtering agents, with unprecedented efficacy. In essence, they work like micro-sponges. They let water containing dirt that is not even visible to the human eye pass through. Being such an infallible system, obviously, its cost is high. However, it guarantees good results.

Which filter to choose?

Although it is true that the quality of a product is important. In this case, this may not be paramount. There are factors such as the budget we have, the commitment to know how to clean the pool water filter and the frequency to do that. Finally, it depends on what is available in the place where you live.

To buy a filter, we must first know the capacity of the pool and the power of the pump. Taking these data as a basis, we proceed to choose the appropriate filter so that the filtration cycle is durable. As a suggestion, we recommend buying a filter above the capacity required by the pool and pump.

Let’s explain this a little better. If we conclude that what we need is a filter of 15m3/h, it’s better to buy one with greater capacity. Thus, its years of life will extend more and the pump will work with more fluidity.

The efficiency of the filters

As we mentioned before, the filtering quality varies according to the installed filter. For example, diatomaceous filters are the best because they filter particles up to 7 microns. This is a big difference if we compare it with the cartridge and sand filter because of these two filter particles of 20 and 60 microns respectively.

To have an idea, let’s take an example: a grain of salt measures 100 microns. We are talking about something that is barely perceived by sight. In fact, the human eye is able to identify objects up to 35 microns. That’s why we say that the diatomaceous filter is very efficient because it filters particles imperceptible to the human eye.

Frequency of cleaning and washing

The first thing that indicates it is necessary to wash the filter is the appearance of the water in the pool. That would be a clear signal that we should wash the filter. However, you should take into account some other factors. For example, the use of the pool will be a factor that will help us to know the frequency with which you should carry out maintenance.

When we visit water parks, we find a number of rules to enter the pool. This is because they are taking care of the life of the filters. Entering the pool with food, drinks or lint-free clothes is harmful to the filters. Now, let’s see what it involves maintaining the different types of filters.

How and when to wash the different types of filters

Sand filters usually have a pressure gauge. In essence, this indicates the water pressure that is passing through it. For example, if under normal conditions the pressure gauge shows 30 PSI and we observe that it has risen to 40 PSI; this indicates that the filter needs washing because water is not flowing smoothly through it.

Cartridge filters are the simplest to wash because of their designs. All you have to do is remove the cartridges and wash them with water at regular pressure.

Meanwhile, in the case of diatomaceous earth filters, they generally offer the backwash system. This is to reverse the flow of water. The idea is that the pressurized water passes in reverse through the filter so that it releases the particles it retains. Later, these particles will go through the drain.

Washing against current

One technique of how to clean the pool’s water filter is counter-current washing. This is because it is the most efficient way to wash the filters. In fact, this is the same technique used to wash the sand filter. In order to know how often we must carry out the washing against the flow, it is necessary to take into account the environment of the pool. If grass or sand surrounds the pool, you’ll need more frequent filter cleanings.

To properly execute the counter-wash we must follow the following steps.

  • Turn off the pump;
  • next, alternate the valves for the backwash position.
  • and then, turn on the pump. However, it is important that once the counter-wash process starts, let the water flow for a long time until it is completely clean.


  • After washing and before running the filter, a rinse is mandatory. This is to reset the sand and evacuate the water that still contains impurities through the drain. Then you have to purge the air that remains in the filters.
  • The automatic selector valves make the process even simpler since they automatically detect that the filter needs a wash. They monitor the pressure of the filter by means of a pressure gauge. Also, they activate the process when necessary. Having a selector valve is very practical as it minimizes human work.

How to backwash a cartridge filter

Because they were not built for reverse water flow, you cannot backwash cartridge filters simply by reversing the water flow in the pool filtration system. You have to clean these filters by hand when they are dirty. Meanwhile, a good cleaning with the garden hose is often sufficient to restore the function of the filter. But chemical cleaning is necessary if you find yourself having to clean the filter every 3 or 4 days. Although the construction of the pool pump varies slightly, the basic process of accessing and cleaning the filter is essentially the same on all equipment.

Step 1

Cut the power supply to the filter. And then, close the valve from the filter outlet that goes to the pool entrance. Next, close the valve that goes from the skimmer to the pump inlet. If you do not have valves at these connections, insert a plug into the skimmer. This helps to stop the flow of water in the pump. Again, insert another plug in the pool entrance to prevent water from flowing back into the filter housing.

Step 2

Next, loosen the air valve on the top of the filter by slowly releasing the pressure and allowing air to enter the cartridge filter housing.

Step 3

Open the filter drain valve. The drain valve is at the bottom of the filter housing. The goal is to empty the trapped water from the filter housing, so as not to recontaminate the freshly cleaned filter when reinstalling later.

Step 4

Remove the top of the cartridge filter to access the cartridge. Depending on the type of cartridge, it may be necessary to unlock a safety device. Refer to the manufacturer’s instruction manual for instructions on how to unlock and remove the top of the filter housing.

Step 5

Lift the filter from the housing and bend it with a garden hose. It is advisable to set the garden hose to the most powerful setting. This helps to remove any debris caught in the cartridge filter. Also, clean the inside of the filter housing.

Step 6

Prepare a chemical solution for the filter in a container large enough to hold the entire pool filter. To prepare the solution, combine 1 cup of trisodium phosphate (TSP) and 4 cups of water. Repeat this ratio until the filter is completely covered in the solution.

Step 7

Allow the pool cartridge to moisten overnight in the TSP solution before rinsing it with the garden hose.

Step 8

Replace the cartridge filter and place the upper rear part on the filter housing. Make sure that the O-ring on the filter housing is positioned correctly and that the housing is locked. Replace the O-ring if it is flat, broken or decomposing.

Step 9

Close the drain valve. Then, open the filter and the pump inlet valves. If you have earlier connected the skimmer and pool return sockets, disconnect them now.

Step 10

Turn on the filter and open the air vent valve on the top of the unit. However, when the water starts spraying, close the air valve. Finally, the cartridge filter is now ready to clean the pool water again.

We recommend watching the following YouTube video related to the backwashing of pool filters:

How you can contribute to the durability of your pool filter

Good maintenance and knowing how to clean the pool water filter can help it last for years. However, to make it last much longer, it is important to collaborate in its proper functioning. Therefore, to achieve this, we must make use of some tools.

One of the most popular tools to clean the pools is the cleaners because they lengthen the filter’s useful life. We must bear in mind that the water in the pool is getting dirty at the surface level. Then, those particles usually settle at the bottom of the pool. Hence, this is where the cleaner comes in.

The task of a cleaner is to vacuum the bottom of the pool in some way. Of course, there is a great variety of these products. They are different in their characteristics and in their prices. But they all serve the same function. Here, we will show you the different types that exist.

Types of cleaner

Manual pool cleaners

It is a swimming pool item that has a base with a brush and comes with a sliding system. In addition, it is coupled to a handle that extends to be able to work a long distance from the curb. Basically, this makes it unnecessary for the person to have to get inside the pool to perform this task.

At the other end, it contains a flexible hose. The mouth is inserted into the upper opening of the pool. So, it is there where the water and dirt that collects at the bottom of the pool sucks it to transfer it to the filtration system, arranging the selector valve handle in the cleaner position.

Basically, it is a manual system that exists inside the articles to clean swimming pools. It is directed by a person who must pass it all over the bottom of the pool without forgetting any corner. It can be exhausting, especially if the pool gets dirty very often. Meanwhile, it is very effective.

If you want to buy a manual cleaner, visit Amazon.

Automatic cleaners

These are truly the best ally of the cleaning staff. The reason is that, in addition to performing the work automatically, we can also schedule it to perform the cleaning every so often. However, it also has some disadvantages.

The use of these automatic pool cleaners will depend a lot on the structure of the pool. For this reason, it is not always feasible to have one of these to clean a pool.

Within automatic pool cleaners or pool robots, there are two types depending on the operation of this. For example, there are the hydraulic bottoms that can work by pressure or by aspiration. And also, there are electric cleaners. Let’s talk a little about the latter.

Electric cleaners

However, the electric cleaners perform their function independently of the purifier. The same cleaner has a collector that retains the sucked dirt. However, one of the advantages is that you do not need to wastewater at any time, which is a great saving.

Of course, not everything is rosy, the main drawback is its high purchase price. But this certainly compensates for the efficiency of this device to work. However, some prefer to go to the economic way. Nevertheless, everything we do to know how to clean the pool water filter will be worth it. This is because the pool filter will be cleaner only if we keep the bottom of the pool clean.

We hope you have been able to learn how to maintain your pool filter as well as know necessary information which might help you in the course of buying, using and maintaining them. Raise your questions in the comment section. Don’t forget to like and share the article.

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