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What Should Pressure Gauge Read On A Pool Filter?

Is your pool filter's pressure gauge confusing you? You already read the numbers, but you don't have an idea what it indicates. To ease your confusion, we've come to your rescue carrying credible information. So search no more, and read the answers we found for you.

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Generally, a 10-25 psi pressure reading is normal for a pool. However, your swimming pool and pump size may still affect your ideal pressure reading. That's why the given pressure reading is just a range you can base from, not a precise measurement.

On the other hand, if you had written down or remembered your initial pressure reading when you first bought your pool filter, this reading should be what you should aim to always have for your pool.

Do you still have many questions left about your pool filter pressure? How would you know if the reading is too high or low? And what should you do to fix a terrible pressure filter reading? Well, we've got all the answers you need, so don't hesitate to scroll down and read further.

A pressure gauge on swimming pool sand filter, What Should Pressure Gauge Read On A Pool Filter?

Ideal Pool Filter Pressure Gauge Reading

Ideally, the range of a standard pool filter pressure reading should be 10-25 psi. Additionally, your pool and pump size determine what the precise good temperature reading is for you.

Pressure gauge measuring water pressure in a sand pump of an outdoor pool filtration system

It's better if you have noted the initial reading from your pressure gauge upon your first use of your pool filter, as this is the optimal pressure your pool should keep. But, if you haven't done this, you can base what a good reading is for your swimming pool according to the psi range mentioned above.

A pressure reading above ten psi from the mentioned range or initial reading is considered too high. Meanwhile, a reading below five psi of the ideal amount is too low. If your pressure reading falls into one of these cases, there must be a problem with your pool, pool filter, or pressure gauge that you must fix.

How To Reduce High Pool Filter Pressure Gauge Reading

Have you found out that your pool's pressure gauge is over the limit ready? Too high pressure works your filtration system much harder than it should, causing damage to the impeller and the motor, so it needs to be fixed immediately.

High-pressure readings are common for swimming pools and are often easy to fix. There are different reasons why you are experiencing this issue, so here's a list of how you must address each of them:

1. Clogged Filter

Swim spa filters

Typically, if dirt from your pool accumulates in your filter, it causes high pressure as water starts to backflow. That's why you must clean your filter to resolve the issue. There are different filters, and cleaning them requires specific procedures too. 

Diatomaceous Earth (DE) and Sand Filters

Clean DE and sand filters through backwashing, which is generally done by doing these steps:

  1. Turn off the pool pump and attach a backwash hose.
  2. Set the valve into backwash and get the pump back on, which usually lasts for two minutes before the filter gets clean.
  3. Put the valve to "rinse" for as long as 30 seconds. For DE filters, you must refill them after.

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Cartridge Filters

Ensure to clean the cartridge filter using muriatic acid by doing this:

  1. Shut down your pool pump.
  2. Open your filter tank and ensure to release the pressure first before taking out your cartridge filter.
  3. With a ratio of 20:1 of muriatic acid and water, fill up a clean trash can or small tank.
  4. Soak the cartridge inside the trash can or small tank with the muriatic acid solution for an hour.
  5. Using a garden hose, rinse the cartridge filter before reinstalling it.

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2. Wrong Water Jet Size

A pool jet fitting that's too small is too restrictive, which causes the pressure in your pool to build up. Check if this is the issue by removing your jet fittings and observing if the pressure goes back to normal after you do so. If it does, you will need to buy a larger jet fitting,  but if it doesn't, there must be another issue present.

3. Unremoved Winterizing Plugs

When left in, winterizing plugs prevent the water in your pool from flowing, causing an increase in water pressure. It's pretty easy to fix, as you only have to check if there are winterizing plugs left and remove them all.

4. Clogged Breather Tube

The breather tube removes the air trapped in your filter. That's why if it gets clogged, air will build up and cause a rise in the pressure. To fix it, do these:

  1. Turn off everything, release the pressure in your filter, and open the breather tube.
  2. Check if there are cracks in the tube. You should replace it if it has cracks or looks old or damaged.
  3. Check if there is debris in the tube and use a hose to wash it. After, you can reattach the breather tube and turn on your pump to see if the pressure goes back to normal.

5. Close Diverter Valves

If your pool has a diverter valve, ensure they're not closed even for a little as the water wouldn't properly flow if this happens, resulting in high pressure. Open the closed valves, and your pressure should return to normal.

6. Wrong Pump Or Filter Size

Your pump's horsepower and flow rate should be compatible with your filter's flow rate. So, if your filter's flow rate is too low to handle your pump, there will be a rise in pressure. Resolve this by using a smaller pump or changing its impeller with a smaller one. Meanwhile, you only have to lower the speed setting if you have a variable or speed pump.

How To Increase Pool Filter Gauge Reading

Split underwater view of a chlorine floater dispenser in a private swimming pool

Is your pool filter gauge reading too low than normal? If so, you can quickly reduce the pressure by doing this:

  1. Add water to your pool. Low water levels affect lower pool pressure, so it's a must that the water is in an appropriate amount.
  2. Your skimmer basket is located on the pool's side, connecting to the filter via a hose. Clean this by opening the skimmer lid, removing the basket, and emptying any dirt or debris.
  3. Shut off the filter and open your pool pump. Another basket is located inside the pool pump that you can access by turning the tip of the pump. Clean this basket if it is clogged by using a garden hose to wash it.
  4. Check if there are cracks it leaks in your pool hoses. Then, if there are, replace them, as they can be the culprit for your low pool pressure.

When Should You Replace Pool Filter Pressure Gauge?

Have you tried fixing every issue there could be for your high-pressure reading? If yes, then your pressure gauge may be the one that's causing the problem itself. Over the years, pressure gauges have worn out, so you will need to replace them. But how do you determine if it's time for a replacement? Knowing if you need a change in your pool pressure gauge is easy. Here are the signs you need to be wary of to know when to buy one:

  • Broken glass shield.
  • Bent dial.
  • Stripped or damaged threading.
  • The pump is off, but the pressure gauge doesn't turn to zero.
  • Stucked needle.

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How Do You Change Pool Filter Pressure Gauge?

Pressure gauge on swimming pool sand filter

Replacing a pool filter gauge can be done fast as it doesn't require long and complex steps. After you buy a new gauge, follow these steps to change your old and worn-out ones:

  1. Shut off your pool pump.
  2. Release the pressure by turning the air relief valve counterclockwise.
  3. Loosen the gauge by turning it counterclockwise with a wrench.
  4. Detach the pressure gauge from the fitting on the filter head top.
  5. Attach your new pressure gauge to the fitting.
  6. In a counterclockwise direction, wrap three plumber layers on the gauge's threading.
  7. Tighten the pressure gauge on the filter head top with your hands.
  8. With a wrench, tighten the gauge again.
  9. Turn the pool pump back on and shut off the air relief valve as water begins to spray out.

In Closing

Generally, you should read 10-25 psi from your pool pressure gauge, as this is the normal pressure range for pools. But note that if you want the precise psi amount, because your swimming pool and pump size may affect what an initial reading is for you, you must note down the first reading your gauge had from your swimming pool. 

Ensure that the reading falls within the given range because a reading way over or below the limit may damage your filtration system. 

Read these posts about how to manage swimming pools for more information:

What To Do After Filling The Pool [And How Soon To Start Swimming]

Outdoor Pool Vs. Air Temperature: Is The Water Warm Enough To Swim?