Backwash Pool Filter to Keep Your Pool Clean and Hygienic

What is backwashing? Do I really need to backwash pool filter? How often? How can I do it? In this article, we will be answering in detail all these questions about the backwash pool filter. Let’s get into it!

When you first hear the word backwashing, it may sound like you’re scrubbing someone’s back. Well, it’s somewhat close. 

But kidding aside, backwashing is a vital pool maintenance procedure. But you may wonder: What is backwashing? Do I really need to backwash a pool filter? How often? How can I do it?

In this article, we will be answering in detail all these questions about the backwash pool filter. Let’s get into it!

What is the Purpose Of Backwashing A Pool Filter?

To get our heads wrapped around the idea of why you need to backwash your filter, we need to first understand the role that your pool filter plays in the filtration system. 

In the pool filter system, the pump creates pressure to circulate the pool water into the filtration system. As the pool water circulates, it goes through your pool filter which then traps the dirt and debris. This filtering process helps maintain the pool clear and hygienic.

Backwash Pool Filter to help clear them up and restore your water flow.

Your pool filter is able to trap contaminants because it is composed of closely packed materials that only let pool water pass through it. Over time the trapped contaminants like dirt and debris accumulate on the pool filter, which will result in losing the effectiveness of your filters.

To remove the accumulated dirt and other particles on the filter, we need to clean it. Backwashing cleans your pool filter by reversing the water flow and redirecting it towards your waste pipe.

Quoting Henry Miller, an American writer, “Nine-tenths of our sickness can be prevented by right thinking plus right hygiene — nine-tenths of it!.” True enough, keeping up pool hygiene can prevent our family and friends from getting sick. And that is why backwashing is important. 

How Often Should You Backwash a Pool Filter

As a rule of thumb, a pool owner may backwash once a week. But you can adjust the backwash schedule depending on a number of factors such as usage, location, and treatments done.

Frequent pool usage increases the volume of dirt, debris, and particles carried by the swimmers. And if your pool location is dusty and windy, you might also need to consider increasing the number of backwash per week.

One indicator that you’ll need to backwash your pool filter is the water pressure gauge. The normal operating pressure of a pool filter is around 8 psi to 10 psi. So if the reading on the pressure gauge exceeds that amount, then it’s time to backwash your filter. Another thing to take note is that most pool filter manufacturers include pressure gauges which have markings to indicate whether the pressure is ok or not.

What Types Of Pool Filters Can You Backwash?

Currently, there are three types of pool filters: sand filter, cartridge filter, and diatomaceous earth filter. Let’s talk about its characteristics, design, and whether you can backwash it or not.

First, the sand filter. As the name implies, it uses sand as its filter medium. The pump pressures the pool water to pass through a tank filled with sand. Due to this design and build, you can backwash your pool sand filter. [1]

The second type is the cartridge filter. This type uses a thin filtering membrane or material such as polyester fabric. Its thin membrane is wrapped around the wires of the cartridges which acts as its support. Sadly, you can’t backwash this filter because its membrane does not allow a reverse flow of water.[2]

Backwash Pool Filter - Cartridge Filter

Lastly, the diatomaceous earth filter or DE filter. This type uses diatoms or sedimentary earth as its filtering medium. Costly but can filter out smaller particles than other types. Its design is quite similar to a sand filter but the main difference is that it has grids or septums that hold the filter medium. Like the sand filter, you can backwash this type of pool filter. [3]

Types Of Valves Used To Backwash Your Pool

Backwashing your pool filter usually involves using valves to choose the flow setting. And there are two types of these which you’ll be encountering-the push/pull valve and the multiport valve. We will be briefly discussing each and how to operate it. 

Push/Pull Valve

Another name for this, is the slide valve. The name refers to the sliding action or push and pull action that you’ll need to do to switch the setting.

This valve is a straight hollow tube with two protruding openings on each side. In the middle of the valve, there is a plunger in the middle that you can slide up and down which changes where the water flows. Due to this design, the push/pull valve only has two settings: filter and backwash. 

Multiport Valve

As the name implies, this type of valve in the pool system has multiple settings. To choose the setting, you’ll need to turn the locking lever handle.

Usually, a multiport valve has seven settings: filter, backwash, winter, closed, waste, recirculate, and rinse. We won’t be talking about that in detail here since what we will be only using three out of the seven-backwash setting, waste setting, and rinse setting. As we go along the procedure, you’ll understand what each means.

Now that all the important questions are out of the way, let’s move on to how to backwash a pool filter.

How To Backwash A Pool Sand Filter

Let’s first start with how to backwash a sand filter. Don’t worry, the steps are easy to follow. [4]

Backwash Pool Filter - Sand Filter

Step 1: Power Off The Pool Pump

The first critical step in backwashing is to make sure that you turn off the pump. This is important because it prevents damage to the valve.

To further explain its importance, when the pump is on it generates pressure in the system. And when you turn the valve handle, it throttles the flowing poo water which creates a water hammer. The force of the generated water hammer will impact and damage the valve and other connectors.

Step 2: Set The Valve To Backwash

After making sure that you’ve turned off the pump, change the valve setting to “backwash.” This setting will reverse the flow direction of the pool water and redirect it to the waste pipe.

Kindly take note that there are filter tanks which don’t have a waste pipe, so be sure to check yours. If the waste connector is left open, you’ll need to prepare a backwash hose and connect it to the proper drain pipe.

Step 3: Turn On Pump

When everything is ready, turn the pump back on. Let it run for 3 to 5 minutes depending on what is indicated on the manual of the filter and wait until the sight glass is clear. Turn the pump off.

If the system pressure remains high even after backwashing, then repeat the backwash and rinse process. In case the problem still persists, then there might be other problems in the filter system or you might need to replace the sand inside the tank.

Step 4: Rinse The Filter

Once done with backwashing, it’s time to set the valve “to rinse.” The “rinse” setting sets the direction back to its normal operation. But the water does not go back into the pool, instead it goes to the drain or waste pipe.

After rinsing, it’s time to set the valve’s setting to “filter” to return it back to normal operation. Monitor the pressure

How To Backwash A Pool Diatomaceous Earth Filter

The process of backwashing a DE filter is very similar to the sand filter with a few minor additions. Again, fear not, it’s easy to do. [5]

Backwash Pool Filter - DE Filter

Step 1: Power Off The Pool Pump

Similar to the backwash process of the sand filter, the first critical step in backwashing is to make sure that you turn off the pump. As a reminder on its importance it prevents damage to the pool filter system. Using valves while there is water pressure can create a water hammer which is very destructive.

Step 2: Set The Valve To Backwash

After turning off the pump, change the valve’s setting to “backwash.” Again, the “backwash” setting will reverse the direction of the pool water and redirect it to the drain pipe.

Be sure to check if your filter tanks don’t have a drain pipe. If the drain pipe connector is left open, you’ll need to prepare a backwash hose and connect it to the proper drain pipe.

Step 3: Turn On Pump

When everything is ready, turn the pump back on. Let it run for 3 to 5 minutes depending on what is indicated on the manual of the filter and wait until the sight glass is clear. Turn the pump off.

If in case the system pressure remains high even after backwashing, then repeat the backwash and rinse process. Just in case the problem still persists, then there might be other problems in the filter system. So you might need to replace some parts of the filter or you might need to manually disassemble it and clean the septums of the filter.

Step 4: Rinse The Filter

Similar to sand filters, after backwashing set the valve to “rinse.” To clear out any remaining debris. If the sight glass is still not clear or the operating water pressure is still not normal, repeat the “backwash” and “rinse” process.

Step 5: Turn On The System And Add DE Powder

When you backwash a pool DE filter, the diatomic earth powder inside gets washed out as well. So you’ll need to replace the lost powder.

To do so, keep your pool pump running and find the skimmer closest to the pool pump. Carefully pour in the skimmer the specified powder amount in the product manual. Monitor and if the system is running fine, then you’re done.

Tips And Reminders While Backwashing Your Pool Filter

Just some tips and reminders below to keep in mind while you backwash. These are essential in keeping your pool water clean and clear.

  • Check chemical levels after backwash – Backwashing involves wasting water into the drain, that is why you’ll need to introduce fresh water into the system. Introducing fresh water will mess up the balance of chemicals so you’ll need to watch out for that.
  • Use a pool cover and shower before taking a dip in the pool – These tips will reduce the dirt and debris entering your pool. Reducing the filtering load from your system.

Summary

In summary, backwashing is an easy and automatic way of removing the accumulation of particles trapped in the filter which results in an increase in the efficiency of the system.To keep your pool clean and clear, it is important to keep a regular backwash schedule

Among the types of filter, sand filters and DE filters are the only ones that can be backwashed. Cartridge filters have to be manually removed and cleaned.

The steps of backwashing are simple and easy to follow-just turn off the pump, set the push/pull or multiport valve to backwash, turn on the pump, and rinse. 

Backwashing is very easy to do, and we believe that you can do it too!

Is there a pool flick you watched or would you like more information on pools? Here are some articles you may be interested in.  

  • [1] https://hayward-pool-assets.com/assets/documents/pools/pdf/manuals/IS311SX1.PDF
  • [2] https://www.google.com/url?q=https://www.pentair.com/content/dam/extranet/pentair-pool/residential/manuals/filters/clean-and-clear-rp/clean-clear-rp-cartridge-filter-manual-english.pdf&sa=D&source=editors&ust=1617089770934000&usg=AOvVaw2RN7xyAB56I0QIfyyY7Pfn
  • [3] https://hayward-pool-assets.com/assets/documents/pools/pdf/manuals/IS311SX1.PDF
  • [4] https://www.pentair.com/content/dam/extranet/product-related/product-manuals/pool-and-spa-equipment/filters/Sand_Filter_Installation_and_Users_Guide_English_Spanish_French.pdf

Leave a Comment