Built-In Filter: Pressure vs Suction Pool Cleaners

What Does Built-In Filter Mean in a Pool Cleaner?

A built-in filter in a pool cleaner is any filter media or debris bag that is part of the cleaner itself, rather than relying on the pool's main filter. Robotic cleaners are the clearest example: ENERGY STAR notes that robotic pool cleaners collect dirt and debris in built-in filters, running on low-voltage electricity. Suction-side and pressure-side cleaners, however, take different approaches to debris collection.

Suction-side cleaners connect to your pool's skimmer or a dedicated vacuum line and use the suction from your main pump to pull water and debris into the pool's circulation system. Pressure-side cleaners use a dedicated booster pump to create a high-pressure water jet that loosens debris and carries it into the cleaner's own filter bag or canister. For a deeper comparison of all three types, see our guide to robotic vs suction vs pressure cleaners.

How Suction-Side Cleaners Handle Debris

Suction-side cleaners rely on your existing pool pump and filter. The ENERGY STAR program explains that the pool pump recirculates water through a filter to maintain water clarity and hygiene. A suction-side cleaner simply extends this system: debris enters the cleaner, travels through the suction hose, and ends up in the pool's skimmer basket or main filter. You still need to clean the skimmer basket and backwash or clean the main filter, just like you would without a cleaner.

Because suction-side cleaners depend on your pump's flow, they are best for pools with a properly sized pump and filter. The ENERGY STAR page notes that filtration requires only half the flow rate of running a pool cleaner, so your pump must be able to handle the extra demand when a suction-side cleaner is active. If your pump is undersized, the cleaner may not pick up debris effectively, and your filter may clog faster. Learn more about flow regulation and pump sizing in our dedicated articles.

How Pressure-Side Cleaners Handle Debris

Pressure-side cleaners use pressurized water from a booster pump to dislodge debris from pool surfaces. ENERGY STAR includes pressure cleaner booster pumps in its certified pool pump categories, confirming that these systems require an additional pump. The water jet also helps sweep debris into a built-in filter bag or debris canister that is part of the cleaner itself, separate from the pool's main filter.

This built-in filter bag typically captures leaves, twigs, and other large debris before the water returns to the pool. Because the bag is inside the cleaner, you must empty it regularly. This is different from a suction-side cleaner, where debris goes directly to the pool's filter. For more on how the debris path works, see Filter Bag vs Debris Canister for Pool Cleaners and Pressure-Side Pool Cleaner Sweep Hoses.

Comparing Filtration Approaches

The key difference is where debris ends up. A suction-side cleaner sends everything to your pool's filtration system, so you rely on the main filter to capture fine particles. A pressure-side cleaner with a built-in filter bag keeps larger debris out of the pool filter, reducing the load on the main filter. This can be useful if your pool has a lot of leaves or if your main filter clogs quickly.

Your choice also depends on your existing equipment. Suction-side cleaners work with your current pump and filter, while pressure-side cleaners require a booster pump. ENERGY STAR points out that conventional single-speed pumps are set to run at the higher speeds required for pool cleaning, wasting energy during lower-speed filtration. A variable-speed or ENERGY STAR certified pump can match the speed to the task, which is worth considering for either type. See our article on pool-cleaning pump usage for more detail.

Another consideration is filter maintenance. With a suction-side cleaner, you will need to clean your main filter more frequently because all debris, including fine particles, passes through it. With a pressure-side cleaner, the built-in bag catches larger debris, but you must empty and rinse the bag after each use to maintain water flow. Over time, you may also need to replace the bag if it tears or becomes clogged. For guidance on keeping your filter in good shape, refer to our filter cleaning frequency article.

Impact on Pool Pump Energy

The type of cleaner you choose affects how much energy your pool pump uses. ENERGY STAR states that a conventional single-speed pump runs at high speed to support a pool cleaner, even when only filtration is needed. This wastes energy. A variable-speed pump can be programmed to run at lower speeds for filtration and higher speeds only when the cleaner is active, reducing energy consumption significantly.

For pressure-side cleaners, the booster pump itself is an additional energy user. ENERGY STAR includes booster pumps in its certification program, meaning they can also be more efficient than standard models. If you already have a booster pump, a pressure-side cleaner makes sense. If you are looking to minimize equipment and energy use, a suction-side cleaner that uses your existing pump and filter may be a better choice. For a broader view, see our article on Pool Cleaner Energy Use.

Choosing the Right Cleaner for Your Pool

If you want to keep debris out of your pool filter and are comfortable emptying a filter bag after each cycle, a pressure-side cleaner with a built-in filter may be a good fit. If you prefer a simpler setup that uses your existing pump and filter, a suction-side cleaner is often easier to install and maintain. For pools with heavy leaf accumulation, a pressure-side cleaner's built-in bag can be a practical way to reduce main filter cleaning.

Think about how much time you want to spend on maintenance. Suction-side cleaners require you to clean the skimmer basket and main filter regularly, but you do not have a separate bag to empty. Pressure-side cleaners require you to empty and clean the bag after each session, which can be messy if you have a lot of leaves. Robotic cleaners offer a third option: they have their own built-in filters and do not rely on your pool pump at all, as ENERGY STAR notes. They run on low-voltage electricity and collect debris in the unit, making them independent of your pool's hydraulics. If you are open to a robot, see our guide to best robotic pool cleaners for more. Also review Pool Cleaner Filter Types to understand filter media options.

What to pick for your use

Questions

What is a built-in filter on a pool cleaner?

A built-in filter is a filter bag or canister attached to the cleaner itself, as opposed to relying on the pool's main filter. Pressure-side cleaners often have one, while suction-side cleaners send debris to the pool's filter.

Do suction-side cleaners have filters?

Suction-side cleaners do not have a separate built-in filter; they use the pool's skimmer basket and main filter to capture debris.

Do pressure-side cleaners require a booster pump?

Yes, pressure-side cleaners use a booster pump to generate the water pressure needed to move and collect debris. ENERGY STAR includes pressure cleaner booster pumps in its certified pool pump categories.

How often do I need to empty a pressure-side cleaner's filter bag?

It depends on debris levels, but you should check the bag after each cleaning cycle and empty it when it is about two-thirds full to maintain performance.

Can a suction-side cleaner handle large leaves?

Suction-side cleaners can pick up larger debris, but it must pass through the hose and into the skimmer or main filter. If you have large leaves, a pressure-side cleaner with a bag may be easier on your filter.

Are robotic cleaners considered built-in filter cleaners?

Yes, robotic cleaners have built-in filter bags or cartridges and operate independently of the pool pump and filter. They are a third option that offers self-contained filtration.