Pool Cleaner Filter Types: Bag, Cartridge, and Screen Compared

The three filter systems at a glance

Pool cleaner filters fall into three broad categories: bag, cartridge, and screen. Each uses a different mechanism to trap debris, and each has its own trade-offs. The right filter for you depends on the size and type of debris in your pool, the frequency you want to clean the filter, and the overall performance you expect from your cleaner.

The table below summarizes the relative differences. For a deeper look at the numbers behind filter performance, see the guides on micron ratings and debris bag capacity.

Bag filters: maximum debris capacity

Bag filters are typically found on robotic and some suction-side cleaners. They consist of a fabric or mesh bag that collects debris as water passes through. The bag's primary strength is capacity: it can hold a large volume of leaves, twigs, acorns, and other bulky debris before needing to be emptied. This makes bag filters ideal for pools surrounded by trees or in windy areas.

The trade-off is that bag filters are not designed to capture very fine particles. They let small dirt and dust pass through, and their filtration is relatively coarse. You'll also need to empty the bag frequently because the large capacity encourages big debris, but once full it stops working effectively. Bag filters are easy to empty: you open the zipper, dump the debris, and rinse the bag. Some bags have a fine mesh liner that catches more dust, but they also fill up faster.

Cartridge filters: fine filtration for clear water

Cartridge filters are common on high-end robotic cleaners and many pressure-side models. They use a pleated fabric element that captures fine particles, including dust, pollen, and algae debris. Because of their increased surface area, cartridge filters can hold a good amount of debris while still maintaining suction and trapping finer material than a bag.

Cartridge filters are easier to clean than bags: you simply rinse them with a hose, and they dry quickly. They do require periodic replacement as the pleats wear out, and they can clog if you have very large leaves. Cartridge filters are available in different micron ratings, which indicate the size of particles they can trap. A finer cartridge will make the water clearer but may require more frequent cleaning if the debris load is high. Most robotic cleaners with cartridge filters have a rinseable pleated filter that lasts many seasons when cared for properly.

Screen filters: simple and coarse

Screen filters, also called mesh filters, are the simplest type. They consist of a metal or plastic mesh that catches only the largest debris, such as leaves, grass clippings, and small rocks. They are not effective at removing fine particles like silt or pollen, and they offer the lowest filtration capacity.

The advantage of screen filters is their cleaning ease. A quick rinse with a garden hose removes the trapped debris, and they never need replacement unless damaged. Screen filters are not suitable for fine debris or for pools with high algae growth. They also let small particles pass back into the pool, which can lead to cloudy water. If you only have occasional leaves and grass, a screen filter is plenty. They are often found on basic suction-side cleaners and are a good choice for pools with minimal debris, where you want a no-fuss filter that you can clean in seconds.

Choosing the right filter for your pool

Your choice of filter type should match the debris you typically encounter and how often you're willing to service the cleaner. If you deal with heavy leaf fall, a bag filter gives you the most capacity between empties. If you want the clearest water and don't mind periodic cartridge rinsing, go with a cartridge. If your pool stays relatively clean and you prefer minimal maintenance, a screen filter will do the job.

Also consider the type of cleaner you want. Robotic pool cleaners often come with either bag or cartridge filters; you can see our picks for robotic cleaners to compare filter types. Suction-side cleaners frequently use screen filters, which is one reason they are budget-friendly; explore our suction-side guide for more. Pressure-side cleaners typically use a bag or cartridge, as covered in the pressure-side roundup.

The amount of time you want to spend on maintenance is another key factor. Screen filters require the least time: a quick rinse and you're done. Cartridge filters take a few minutes of rinsing and a monthly deep clean. Bag filters demand emptying after heavy use, which can be messy but is straightforward.

Filter types across cleaner categories

Robotic pool cleaners are the most likely to offer bag or cartridge filters. Because they run on low-voltage electricity and collect debris in an onboard filter, they can be designed with either a large bag for leaves or a fine cartridge for dust. Suction-side cleaners connect to your pool's pump and often use a screen filter, letting the pump's filter handle fine particles. Pressure-side cleaners use a booster pump and typically feature a bag or cartridge to catch debris before it reaches the pool pump.

Above-ground pools often pair with suction-side cleaners because of the low initial investment, while in-ground pools give you more flexibility to choose a robotic or pressure-side model. If you're considering a specific cleaner type, see our above-ground guide and our in-ground guide.

Keeping your filter in top shape

Regular filter maintenance ensures your pool cleaner continues to perform. Empty bag filters when they are about two-thirds full to avoid loss of suction. Rinse cartridge filters after each use and deep-clean them monthly with a filter cleaner. For screen filters, a thorough rinse after every cleaning session is usually enough. Replace any filter when it shows signs of wear, such as tears or cracks.

When you store your pool cleaner, remove the filter and let it dry completely. A damp filter can develop mold or mildew. For bag filters, empty and rinse them before storing. Cartridge filters should be cleaned and allowed to air dry. Screen filters can be stored in the cleaner, but check for any stuck debris.

For a full routine, see the guide on how to clean a pool cleaner and the article on filter cleaning frequency. You can also find replacement filters when yours wears out.

What to pick for your use

Questions

Which filter type is best for leaves?

A bag filter, because it can hold a large volume of leaves and other bulky debris before emptying.

Can I change a screen filter to a cartridge filter?

Usually not; the filter type is built into the cleaner. If you want finer filtration, you'll need a cleaner that supports a cartridge filter.

How often should I clean the filter?

It depends on usage and debris load. For bag filters, empty when about two-thirds full. Cartridge and screen filters should be rinsed after each use and deep-cleaned periodically.

Does a cartridge filter improve water clarity?

Yes, because it captures finer particles than a screen or bag, leaving the water visibly cleaner.

Are bag filters messy to empty?

They can be, but you can rinse the bag out after emptying to reduce mess and extend its life.