How to Increase the Suction Of Your Pool Skimmer

Written by Michael Dean
December 7, 2023

pool skimmer with question mark

Pool skimmers are essential to your pool’s filtering system and are necessary to clean out pool debris. They work by suctioning water through an opening, sieving the debris using a strainer basket, and then sending the cleaned water back outside – ensuring a steady circulation of clear and healthy water. Naturally, if the skimmer’s ability to suction water gets low, it will have difficulty pulling the water for cleaning.

This is a relatively common issue that lowers the efficiency of your filtering system, so have a look below at some primary causes and solutions to sort it out. For more tips on solving common skimmer issues, head over to my complete guide on how to solve common pool skimmer problems.

Main Takeaways

  • Your pressure gauge should alert you to low suction problems.
  • Low suction is often caused by a blockage in the pool equipment.
  • The key player in all suction-related issues is your pool impeller, so service it regularly.
  • Clean everything once a week to prevent a build-up of debris.

How Do You Know if Your Skimmer’s Suction is Low?

Have a look at the pressure gauge of your filter tank. First, figure out your tank’s optimal flow rate (follow the manufacturer’s instructions if you’re uncertain), and you’ll know the base or starting pressure for your filter.

Next, backwash the filter and the pump basket to reset the PSI to a normal functioning range. Now restart the pump and let it run as usual. Following this, if the PSI either rises around 5-10 pounds on the gauge or reads lower than average, you’re looking at a low suction problem.

Depending on your filter model, the PSI should hover between 10 and 25 – anything above or below that much is abnormal.

If your pressure is higher than average, there is likely an obstruction after the pump. If it is lower than average, your obstruction is at or before the pump – on the suction side of the system.

Other problem signs include:

  • Bubbling noises
  • A loud pump
  • A slow return on water jets
  • A dirty pool filled with dead leaves and insects

How to Increase the Suction in Your Pool Skimmer: Causes and Solutions

Low suction may sound like a simple issue, but it has a highly negative impact on the functioning of your pool. Here are some ways you could fix the problem if you notice that the suction of your pool skimmer is low.

Low Water Levels

If your pool water is low, your skimmer may struggle to pull in water for cleaning. Low water levels can cause bubbling, overheating, or sucking in air, potentially overstraining the filtering system.


The fix is quite simple. Open the valve that fills your pool and make sure it reaches the recommended levels for the size of your pool and your skimmer. The water level must be at around half of the opening of the skimmer to ensure a steady state of water pressure.

Stained Cartridge Filters

All other parts of equipment should operate in sync for your pool to be clean. Check your entire pool filtration system, specifically your cartridge filters – they might be filthy, blocked, or need replacement. If you see worn or frayed bands, flattened pleats, cracked end caps, or an extremely persistent oiliness to your filter, this could be what’s causing low suction in your pool.


Soak the cartridge filters in a cleaning solution overnight to clean out all the grease, and make sure the filter is cleaning the water effectively. If they remain brown despite this, I recommend replacing them entirely. If you use a sand filter, the sand might be old. Replace the sand.

Skimmer Basket Blockage

Check if your skimmer basket is free of any blockages. The skimmer basket permits the overflow of surface water into a suction pipe that goes to the filter – if this is blocked, it could shut down the pipe between the pump and the skimmer, leading to lower water pressure.


Remove the basket and clear out all collected material (use a pair of gloves, it can get quite dirty). Once all blockage has been removed, spray it down with water. I recommend setting up a regular schedule to do this. You can use a pool skimmer sock to prevent future buildup.

Clogged Impeller

The impeller is a vital part of the pool pump. It’s what pushes and pulls the water out for cleaning. If something has blocked it, it could be why your pool’s suction is low.


Clean out your impeller. If the problem persists, examine your pool basket – it could be broken, and this is what could be causing debris to repeatedly block the impeller. Since the impeller maintains suction, it needs to be at the top of your list for regular maintenance checks.

Jammed Skimmer Suction Line

Skimmers have two main lines: return and suction lines. Since return lines only deliver clean water, a potential blockage would be located in the suction lines. An unusually loud pump with low suction is a possible indicator of this issue.


Once you’ve run a few tests and figured out which suction line is causing the problem, close the other intake lines. The clogged line should be the only one open. Remove the pump’s lid, place your garden hose within to force water down the line, and dislodge the blockage with the water’s pressure. This should free up the pipe. If the blockage persists, however, hire a professional to take a look.

Air Leaks

An air leak in your skimmer is never a good sign. Think of how difficult it is to sip a drink with a straw that has a hole in it. Air leaks are frequent and could be caused due to faulty valves, loose drain plugs, low water levels, blockages, or clogged impellers.


There are many reasons for an air leak, but the most common and easily fixable issue is a loose pump lid. Check for cracks in the lid, or try opening it and reattaching it very firmly. Give it a few extra turns to ensure it forms a tight seal.

If this doesn’t sort it out, try servicing all your o-rings. Open and remove any caskets, valves, and lids containing o-rings, clean them thoroughly, lubricate them, and replace them properly to form a tight seal. Run the skimmer again.

If you still see issues with air leaks after troubleshooting, hire a professional to fix the problem.

Dirty Pre-Pump Filter

The pre-pump filter is one more place you could check to see if it requires cleaning. It’s a filter near the skimmer’s filter that catches larger debris. This filter usually has a semi-transparent cover. If it looks dark inside, it could be clogged and need cleaning.


Open the lid, remove the plastic filter, and hose it down with water. Check for cracks or leaks inside after cleaning to ensure nothing is broken. Once you replace it, firmly tighten it by hand to ensure the seal is in place. Once returned to its place, the suction should run without any issues.

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Improving Skimmer Suction Is An Easy Fix

Low suction is usually caused by a build-up of debris blocking a few important parts of your filtering system. Clean your pool weekly in all the problem areas mentioned above to ensure that build-up does not occur. If you have a busy schedule and cleaning once a week is too much work, or you’re still encountering a low suction problem with your skimmer, it might be a good idea to hire a professional to do this grunt work.

More questions? Let me know! Also, check out my related skimmer research below.

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