When should a pool filter be backwashed?

Author: Connie Steuber  |  Last update: Friday, February 28, 2025

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.

How do I know when to backwash a pool filter?

If your filter has been running for 48 hours straight without stopping then you will need to perform a backwash. D.E. will "settle" onto your filter grids whenever it runs without stopping. This can cause a buildup of pressure even if your filter grids are clean.

How often should I backwash my water filter?

One way to make the when-to-backwash decision is to install pressure gauges before and after the filter. Backwashing should be performed when the pressure drop reaches a pre-determined maximum value (typically 15 PSI for whole house systems).

Do you backwash the pool before or after shock?

Yes you can backwash the morning after shocking. My rule of thumb is back wash until clean, rinse 10 seconds, backwash again, rinse 10 seconds, Obviously turning off the system between each step. Set filter to Filter and open pressure valve.

Do I need to add de after every backwash?

You MUST add new D.E. every time you backwash a D.E. filter or it will lose its effectiveness to clean the water. It is suggested that you backwash your multiport D.E. filter after you vacuum. If necessary, do so before and during vacuuming but remember, add D.E. to skimmer EVERY TIME YOU BACKWASH!

How Often Should You BACKWASH A POOL FILTER?

What happens if you forget to rinse after backwash?

Don't forget to rinse! Rinsing for 30 seconds after backwashing pushes the sand back in place clearing the filter of loose dirty water. If you don't rinse, you will have a puff of dirty water coming through the jet and back into your clean pool.

Can you backwash too much?

Backwashing too often can reduce the filter's effectiveness. The sediment layer helps improve filtration by trapping finer particles.

When should you not backwash a pool?

Backwashing is a great way to clean out clogged filters but there are times you should avoid the process. If your pool has or had an algae issue is it recommended to by-pass your filter entirely and vacuum directly to waste.

What happens if you put too much shock in your pool?

Is it possible to shock your pool too much? Yes—excessive shocking of your pool will keep it at an elevated chlorine level. This will cause irritation of the skin and eyes as well as excessive wear and tear on your pool filter system, including excessive corrosion of all metal parts.

In what order do you correct pool water?

To chemically balance your swimming pool water, follow these eight steps:
  1. Adjust Alkalinity. A pool with low alkalinity has high acidity. ...
  2. Adjust pH Levels. ...
  3. Balance Calcium Hardness. ...
  4. Sanitize. ...
  5. Measure Cyanuric Acid (CYA) Levels. ...
  6. Measure Dissolved Solids. ...
  7. Shock the Pool. ...
  8. Test the Water.

What is the filter backwash rule?

What is the Filter Backwash Recycling Rule? The FBRR requires filtered surface water suppliers using conventional or direct filtration to, where needed, change the return of recycle flows in their plant's treatment process.

How long do I rinse after backwash?

Turn the lever to BACKWASH. Open the valves to the suction and return lines. Start the pump. Rinse the filter for about 1 to 2 minutes or until the water in the sight glass is clear.

Where does backwash pool water go?

To backwash via the waste line is to run your pool water back through the filter, but rather than circulating the water back into the pool, it is flushed out through the waste line. Whilst the backwashing process is flushing out the dirt and debris, so is it flushing out your water with it.

Should you vacuum pool on backwash?

While it's not strictly necessary to backwash before vacuuming, doing so can significantly enhance the efficiency of your vacuuming efforts.

What is the ideal level of chlorine in a swimming pool?

Regardless of how frequently or what system you use to add chlorine to the water, the chlorine level should stay between 1.0 and 3.0 parts per million (ppm) to maintain a healthy pool. Anything higher will make you run the risk of red eyes and swimmers itch.

How do I know if my pool filter is running properly?

There are two main methods to figure this out. You could try adding some diatomaceous earth or a sand filter to test it. Just a scoop or two will do it into the skimmer. Immediately after adding it look at the pool jets and returns to see if you can physically detect cloudy water coming back in.

Do I really need to shock my pool every week?

Hot & Rainy Months: Weekly

During the hotter months of the year, or when the forecast shows a chance of rain, shock your pool weekly. These conditions can significantly increase the chance of algae growth, and a weekly dose of shock will help keep the green away.

Do you add algaecide or shock first?

Algaecides act as a backup to your normal sanitization program and prevent algae from starting and growing in the pool. Algaecide should be added after every shock treatment.

How many cups of chlorine to shock a pool?

For chlorine shock treatment, 3 measuring cups of 40 grams of chlorine granules should be added per 10 m³ of water. Ideally, this should be added after swimming or in the evening to ensure that the product can spread well throughout the pool.

How often should I bump my pool filter?

Bumping should be performed when the pressure on the filter increases 7-10 psi above its normal reading.

What's the difference between rinse and backwash?

What the backwash does is unsettle the sand and push out the fine debris. The rinse then expels the debris and compacts the sand again to prepare the filter to catch more dirt.

How do you avoid backwash?

Instead of putting your whole mouth over the end of the bottle, rest bottom rim of bottle on your lower lip and only drink from half the opening. This allows you to stop the flow without tipping the bottle down stopping backwash from getting into the bottle.

How many minutes should I backwash my pool?

Turn on the pump and allow the sand filter to backwash for 2-3 minutes or until the water in the sight glass (typically located on the top of the filter) is visibly clear. How long you backwash the sand filter for is not critical though you should visibly see clear water within 2-3 minutes.

What problem is created by too high a backwash rate?

If backwash rates are too high, significantly more media could be lost— compromising filter performance. In any case, it is important to measure, track, and replace any missing media during your annual filter inspection and maintenance check.

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