Pool Cleaner Filter Micron Rating: How Fine Is Fine?

What a micron rating means in a cleaner listing

A micron rating is one of the stated details you may see when you read a pool cleaner listing. The word micron names a unit of length: one micron equals one millionth of a meter, the same unit sometimes called a micrometer. In a cleaner title or bullet list, a micron figure describes the size of the finest particle the filter is stated to hold back.

Reading the figure is straightforward in direction: a lower number describes a filter for finer particles, and a higher number describes a filter for coarser debris. The rating belongs to the filter that comes with the cleaner, whether that filter is a bag, a cartridge or a canister. When a listing does not state a micron figure, treat it as unstated rather than assuming a value.

Lower and higher figures describe different debris

Finer and coarser are the two directions a micron rating points to. A filter stated at a low figure is described for fine particles such as dust, pollen and silt. A filter stated at a high figure is described for coarse debris such as sand, leaves and twigs. Which direction suits your pool is a shopping question about the debris your pool collects, not a claim this article makes.

This site does not convert micron figures to other units and does not match a rating to a pool size or volume. The figure is a comparison point between listings. A listing may state the rating, the filter type, or the debris capacity, and those are separate stated details.

Where the rating appears in the listing

In a listing, the micron rating usually appears in the bullet list or in the title as a number followed by the word micron. It can also appear in the image set as a particle-size diagram. Model names rarely carry the figure; feature words such as "fine filter" or "high filtration" describe the filter without a number, and this site reads those as the seller's words too.

When the seller does not state a micron figure, the listing may still carry other filter words you can read: the filter type (bag, cartridge, canister), the debris capacity, and whether the filter is described as fine, medium or coarse. The places to look are the title, the bullet list, the image captions and the maker's manual. If none of those pages state the figure, the rating is not stated by the seller.

• Title line: a number followed by the word micron
• Bullet list: filtration details and filter type words
• Image set: particle-size diagrams or filter close-ups
• Maker's manual: the most detailed stated source
• Absent everywhere: treat the rating as not stated

Filter media and the stated rating

Filter media words such as bag, cartridge and canister describe where the captured debris is held, while the micron rating describes the particle size the media is stated for. The two are separate stated details. A finer rating and a larger debris capacity are not the same claim; a listing may state both, one, or neither. For the media words themselves, see the filtration media article and the filter bag volume article.

Filter life is another separate figure, stated as a number of cleanings or a period of use. This site does not verify filter life across listings as a measured result; it reads the stated figure only. Filter care is a maintenance topic, covered in the filter life article and the filter cleaning methods article.

Robotic, suction-side and pressure-side filters

Which cleaners carry their own filter? A robotic cleaner is a corded or cordless unit with a built-in collection filter. The ENERGY STAR program describes robotic pool cleaners as powered by low-voltage electricity rather than by the pool pump, collecting dirt and debris in built-in filters, which is why a robot listing can state a micron rating for its own filter.

Suction-side and pressure-side cleaners run off the pool pump and use the pool's main filter, so their listings describe flow needs and connection words rather than a built-in filter. For those cleaners, the micron rating you care about belongs to the pool's own filter, a separate purchase. The cleaner types are compared in the robotic, suction-side and pressure-side article, with pump matching in the suction-type pump matching article. If you are pairing a cleaner with a filter pump, the sand filter pumps for above ground pools guide is the place to start.

What this article cannot say about a rating

This article explains the term; it does not rate filters or promise results. This site compares stated details only, and a micron rating is a stated detail, not a measured outcome. A finer figure does not mean the pool will look different to you, and the site makes no claim about water clarity, cleaning performance, or how long a filter lasts.

Industry standards for pool equipment exist: the Pool & Hot Tub Alliance develops national consensus standards for residential pools, as its standards page describes. Those pages do not define a universal micron scale, so the figure in a listing is the seller's own stated value. If a listing does not state the figure, the maker's manual is the next place to look, and the local building office or the maker can answer questions about installation and local requirements.

What to pick for your situation

Questions

What does a micron rating mean on a pool cleaner filter?

It states the size of the finest particle the filter is described to hold back. One micron is a unit of length equal to one millionth of a meter. A lower figure describes a finer filter; a higher figure describes a coarser one.

Is a lower micron rating better?

Not as a ranking. A lower figure describes a filter for finer particles, which suits a pool that collects dust and pollen. A higher figure describes a filter for coarser debris such as sand and leaves. The right figure is a shopping question about the debris your pool collects, not a score.

Where do you find the rating in a listing?

Look for a number followed by the word micron in the title or bullet list, or in the image set as a particle-size diagram. If it does not appear, the seller has not stated it; the maker's manual is the next place to look.

Do cordless robotic cleaners have their own filter?

Cordless robots are robotic cleaners, and robotic cleaners collect dirt in built-in filters rather than running off the pool pump. That is why a robot listing can state a rating for its own filter.

Do suction-side and pressure-side cleaners have a micron rating?

Those cleaners run off the pool pump and use the pool's main filter, so their listings describe flow needs and connection words. The micron rating applies to the pool's own filter, which is a separate purchase.

What if the listing does not state a micron rating?

Treat it as unstated. The listing may still state the filter type and debris capacity in words, and the maker's manual may give the figure. This site reads stated details only and does not fill in a missing number.

Does a finer rating mean the cleaner holds more debris?

No. A finer rating and a larger debris capacity are separate stated figures. A listing may state both, one or neither, and this site does not rank them against each other.