Poolking, your best swimming pool equipment manufacturer and supplier with more than 20 years experience.                                                                              +8613922334815


why is the pressure in my pool filter high


Possible article:

Why Is the Pressure in My Pool Filter High?

If you own a pool, you probably know that maintaining proper water balance and sanitation is essential for its longevity, clarity, and safety. One of the key components of a pool system is the filter, which removes debris, dirt, and other contaminants from the water. However, if you notice that the pressure gauge on your filter shows a high reading, it could indicate a problem that needs attention. In this article, we will explore some possible causes of high pressure in a pool filter and suggest solutions to resolve them.

Understanding Pool Filter Pressure

Before we dive into the reasons for high filter pressure, let's clarify what pressure means in this context. The pressure gauge on a filter measures the force that water exerts on the internal surfaces of the filter elements, which are usually made of a porous material such as sand, diatomaceous earth (DE), or cartridge. The normal range of pressure for a filter depends on its type, size, and condition, but a typical range for a sand filter is 5-15 pounds per square inch (psi), while a DE or cartridge filter may have a higher range of 10-30 psi. When the pressure rises above the normal range, it signals that the filter is clogged or obstructed, and the flow of water is restricted, which can strain the pump, reduce circulation, and create other problems.

Possible Causes of High Filter Pressure

Now that we know what filter pressure is and what range it should be in, let's look at some factors that can cause it to rise abnormally.

1. Dirty or worn-out filter media: Perhaps the most common reason for high pressure in a filter is dirty or worn-out filter media. If the sand, DE, or cartridges are clogged with debris, algae, or minerals, they cannot trap any more particles and become less efficient. As a result, the pump has to work harder to push water through the filter, which can increase the pressure on the gauge. Similarly, if the filter media is old and no longer able to maintain its porosity, it can also lead to high pressure.

2. Pump or plumbing issues: Another possibility is that the pump or the plumbing system of your pool has a problem that affects the filter pressure. For example, if the pump is too powerful for the filter, it can cause high pressure by forcing more water into the filter than it can handle. Alternatively, if the pipes or fittings are leaky, cracked, or obstructed by debris, they can reduce the flow of water to the filter and create backpressure, which can cause the pressure gauge to rise.

3. Chemical imbalances: Although pool chemicals are not a direct cause of high filter pressure, they can contribute to it indirectly. For instance, if the pH, alkalinity, or calcium hardness of the water is too high or too low, it can affect the chemistry of the pool and cause scale or corrosion to form on the filter media. This can reduce its effectiveness and increase the pressure accordingly. Also, if the pool water is too cloudy or foamy, it can indicate a high level of organic or inorganic contaminants that the filter is struggling to remove, which can cause the pressure to increase.

4. Maintenance neglect: One of the simplest reasons for high filter pressure is neglecting routine maintenance tasks such as backwashing, cleaning, or replacing the filter media. If you don't backwash your sand filter, for example, it can accumulate a layer of dirt on top of the sand bed that reduces the flow of water and increases the pressure. Similarly, if you don't clean your DE or cartridge filter according to the manufacturer's instructions, it can get clogged or damaged and cause high pressure.

5. Equipment failure: Lastly, it is possible that your pool filter, pump, or gauge has a mechanical or electrical malfunction that causes high pressure. For instance, if the gauge is faulty or misaligned, it can show an inaccurate reading that makes you think the pressure is high. Or, if the filter's internal parts, such as the manifold, the air relief valve, or the pressure release valve, are broken or missing, they can cause irregular flow patterns that affect the pressure.

Resolving High Filter Pressure

Now that we have identified some possible causes of high pressure in your pool filter, let's see how you can fix them.

1. Clean or replace the filter media: If the pressure gauge shows a high reading, the first thing you should do is inspect and clean the filter media. If it is dirty, backwash the sand filter or take apart the DE or cartridge filter and rinse it with a hose or a cleaning solution. If the media is worn-out or damaged, replace it with a new one. This will restore the filter's efficiency and reduce the pressure.

2. Check the pump and plumbing: If the filter media seems fine, you should inspect the pump and plumbing for any signs of malfunction. Check the pump's settings, flow rate, and impeller for compatibility with the filter. Also, examine the pipes, fittings, valves, and skimmer basket for any obstructions, leaks, or cracks that affect the flow of water. Fix any issues as needed, and monitor the pressure gauge to see if it returns to normal levels.

3. Adjust the chemical balance: If you suspect that the high pressure is due to chemical imbalances, test the water chemistry and adjust it accordingly. Add the right amount of pH increaser, pH decreaser, alkalinity increaser, or calcium hardness increaser as needed to balance the levels. Monitor the water regularly to ensure that the chemistry stays within the ideal range.

4. Perform routine maintenance: To prevent high filter pressure from occurring in the first place, make sure to perform routine maintenance tasks according to the schedule recommended by the manufacturer. This may include backwashing the sand filter every two weeks, cleaning the DE or cartridge filter every three to six months, replacing the filter media every several years, and inspecting the equipment and plumbing regularly.

5. Repair or replace faulty equipment: If you have ruled out all the other causes and the pressure gauge still shows a high reading, you may need to repair or replace the filter, pump, or gauge. Consult a pool professional for advice, or refer to the owner's manual for troubleshooting tips.


High pressure in a pool filter can be a warning sign of various problems that require attention. By understanding the causes and solutions of high filter pressure, you can maintain a healthy and enjoyable pool that lasts for years to come. Remember to monitor the pressure gauge regularly, test the water chemistry frequently, and perform routine maintenance tasks on time. If you need further assistance, don't hesitate to contact a pool expert for advice.


Just tell us your requirements, we can do more than you can imagine.
Send your inquiry

Send your inquiry

Choose a different language
Current language:English