What does backwashing a sand filter do?

Author: Margarete Feil  |  Last update: Monday, June 20, 2022

Well, as the name suggests, backwashing involves reversing the flow of water through your filter media, be it Zeoplus, sand, glass pearls or diatomaceous earth (DE). This dislodges dirt and debris that may have become trapped, and flushes it out through your multiport valve waste line.

How often should I backwash a sand filter?

How Often Should I Backwash? A good rule of thumb is to backwash once the pressure displayed on your pressure gauge is 8-10 psi over the starting level. Backwashing after heavy rains, treating for algae, or when trying to clear cloudy water will keep your filter working efficiently.

What is the purpose of backwashing a sand filter?

The process of backwashing dislodges trapped debris and contaminants, flushing them out through your value's waste line or a hose that is connected to the pool pump. When the filter media is clean, the pressure gauge is lower and water can easily flow in and out of the system.

Do I need to backwash sand filter every day?

Whenever the filter fills up with the dirt/debris it reduces the flow of water to your pool. Low flow = poor circulation which will lead to algae in the pool. Bottom line, the filter must be backwashed on a regular basis to ensure that your pool water is clear.

Do you lose sand when backwashing?

When you first install a sand filter or renew the sand, you may indeed get a small amount of sand coming out when backwashing, rinsing or filtering. Often, excess sand gets into the wrong places when refilling and will sand to come out into the pool or out of the backwash hose. But it should go away after a few runs.

Everything you Need to Know About BACKWASHING your Sand Filter!

Why is there sand in my pool after backwashing?

Your pump may be too large or the sand level too high in the filter. When the filter is backwashing the water flow can cause the sand to rise high enough and overflow into the standpipe, which will allow the sand back into the pool.

Do you rinse or backwash first?

The 'Rinse' setting should be used after backwashing and again run just for a minute or two. On this setting the water is flowing through the filter in the normal direction but once again is being sent to the waste pipe rather than being returned to the pool.

How long do you rinse after backwashing a pool?

Turn the lever to RINSE, start the pump and rinse for about 15-30 seconds. Stop the pump and turn the lever to FILTER. This is the normal operating position. Close the drain outlet valve and start the pump.

Does backwash drain the pool?

It is not recommended to drain a swimming pool through the backwash valve. While sucking from the main drain and putting the water down the backwash line will work in some scenarios it puts your pool pump at risk of losing prime and running dry.

Can you backwash a pool too much?

Can You Backwash Too Much? If you backwash your pool too much i.e. time duration and/or close frequency then yes you can cause a lot of problems. Some problems that can arise from backwashing your sand pool filter too much are: Loss of water – 500+ litres of water can be lost in each backwashing cycle.

Should I backwash after shocking pool?

Backwash only as needed. Brush the pool vigorously, several times after shocking the pool. Do not use a solar blanket until chlorine and pH level are normal. If chlorine level drops to zero within 24 hours, Repeat the shock treatment.

Does pool backwash hurt grass?

* Can i discharge the backwash water onto my lawn, will it harm the grass / plants? The DE doesn't harm the grass or plants, excessive chlorine or saltwater may.

Can a sand filter remove algae?

Slow sand filtration is a rentable biological water disinfection method that is capable of reducing the amount of algae, fungi, bacteria and some viruses (e.g. TMV not) in the water. When combined with aeration, the filter can also remove calcium and iron from the water.

Do you vacuum a pool on backwash or waste?

If you do have this option, it is highly recommended that whenever you have algae, you will need to vacuum to waste. This option allows you to vacuum the algae up and send it out through the backwash line, avoiding getting algae into your filter sand.

Does backwashing lower water level?

For inground pools with a sand or DE filter, the easiest way to quickly lower the water level is to place the multiport valve into the waste position and roll out the backwash hose. If instead, you have a slide (push-valve), backwash the filter to lower the water level.

What do you do with backwash water?

Use the backwash to water grass or any area on your property that will allow water to percolate into the ground. Backwash pools directly into the private sewer cleanout on your property instead of into the storm gutter.

What do I do after I backwash my pool?

Backwashing reverses the flow of water, lifts up and flushes the sand, and then expels the dirty water via a waste line into the ground or drain. In order to prevent residual blow back into the pool, once you've finished backwashing it's highly advisable to rinse the filter.

How often do I need to backwash?

As a general rule, you should be backwashing your pool about once a week or in conjugation with your scheduled maintenance. Another industry standard is to backwash when your filter's pressure gauge reads 8-10 PSI (pounds per square inch) over the starting level or “clean” pressure.

What's the difference between rinse and backwash?

Rinse runs water in the same direction that normal filtering does. Backwash runs it through the sand in the opposite direction. Rinse is to clear any dirt out of the clean side of the sand before you start sending it back to the pool.

What is the difference between backwash and waste on a pool filter?

Drain/Waste: Opting the drain or waste setting will remove pool water without forcing it through the filter. Backwash: This clears out any debris, dirt and other contaminants that may have accumulated on the filter. Closed: if you choose this setting, then the flow of water to the pool and filter will be stopped.

What PSI should my sand filter run at?

Your filter may be clean and normal at 9-10 psi, but your neighbor's filter gauge could run higher, and be clean at 15-16 psi. Some systems with very low resistance can run very low pressures, barely registering, while other filter systems can run quite high, pushing 30 psi when the filter becomes dirty.

Is it better to run your pool at night or during the day?

It's best to run your pool pump during the day

Not only does sunlight give fuel for algae to grow, it also destroys your pool chlorine and this is why you should always run your pool during the day!

How do you point a jet in the pool?

The best way to position your pool jets is angled slightly downward and all pointing at the same direction or depending on the shape of your pool, that will create one “flow” or circular motion in your pool. The direction should be away from the skimmers.

Why is my sand filter blowing sand into the pool?

If you see it blowing out into the pool, something is broken. The most common problem is a cracked lateral, which is one of the perforated pipes at the bottom of the filter that catches water that has circulated through the sand.

How do I know when to add sand to my pool filter?

The sand in your pool filter needs replacing every three to five years, sometimes even longer if your pool remains in relatively good condition when it's open. If you run your pool filter often all year and have a heavy bather load, the sand may need replacing sooner than three years.

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