Pool Cleaner Adapter Fittings: Which Do You Need?

What are adapter fittings?

Adapter fittings are the plastic connectors that join a pool cleaner's hose to your pool's water circulation system. They are not the cleaner itself, but they are essential for suction-side and pressure-side cleaners that rely on the pool pump to move water. Robotic cleaners are self-contained and do not use these fittings, so this article focuses on the other two types. If you are comparing cleaner types, see our guide on suction-side vs robotic cleaners for more context.

On a listing, you might see words like "adapter," "union," "connector," or "skimmer plate." These terms describe the pieces that make the connection possible. The exact fitting you need depends on where you plan to plug the cleaner in: a skimmer, a dedicated suction line, or a return jet. Each connection point has a different standard size and shape. For a full overview of cleaner types, read our best pool cleaner guide.

Types of connections

There are three common places to connect a suction-side cleaner: the skimmer, a dedicated suction line, and sometimes a return jet. Pressure-side cleaners typically connect to a return jet or a dedicated pressure line. Each connection uses a different adapter.

A skimmer connection is the most common for above ground pools and many inground pools. The cleaner hose attaches to a skimmer plate that fits into the skimmer basket opening. A dedicated suction line is a separate pipe in the pool wall, often with a vacuum plate or fitting that the hose plugs into. Return jets are the outlets where water flows back into the pool; pressure-side cleaners may use a fitting that replaces the jet's eyeball. For more on suction-side connections, see our best suction pool cleaners guide.

Reading listing terms for fittings

When you read a pool cleaner listing, look for the connection type in the title or bullet points. A title might say "for skimmer connection" or "includes wall fitting." If the listing says "adapter included," it usually means the cleaner comes with the necessary connector for a specific pool type, but not always for your pool.

Words like "universal" or "standard" are common, but they do not guarantee a fit. The safest approach is to check the maker's page for the exact fitting size and compatibility with your pool's skimmer or suction line. If the listing does not state the fitting, that is a sign to ask the maker before buying. For above ground pools, the best above ground pool cleaner guide can help you compare models.

Common fitting sizes

Fittings come in a few standard sizes, but the exact dimensions vary by brand and model. For example, some suction-side cleaners use a 1.5-inch or 2-inch hose connection, while others use a proprietary quick-connect. The listing may state the size in inches or as a model-specific part number.

You do not need to memorize the sizes. Instead, compare the listing's stated fitting with your pool's skimmer or suction line opening. If the listing does not give a size, the maker's manual will. Never assume a cleaner will fit just because the listing says "for inground pools." For inground pools, our best inground pool cleaner guide lists models with their stated details.

Skimmer plates and unions

A skimmer plate is a flat piece that fits over the skimmer opening, with a hole for the hose. It is common for above ground pools. A union is a threaded connector that screws onto a pipe or fitting. Both are types of adapters.

On a listing, you might see "skimmer plate included" or "union adapter." These are helpful details because they tell you what is in the box. If a listing does not mention a skimmer plate, the cleaner may require one that you buy separately. Check the maker's page for the part number. For more on suction-side cleaners that climb walls, see our wall climbing suction cleaner guide.

What to check before buying

Before you buy a suction-side or pressure-side cleaner, make a list of your pool's connection points. Note the type (skimmer, dedicated line, or return jet) and, if possible, the opening size. Then compare that with the listing's stated fittings.

If the listing is missing this detail, the maker's manual or support page is the next place to look. The manual will show the exact fitting and how to connect it. This is also where you will find any additional adapters you may need to buy separately. For a broader look at pool cleaner types, see our best pool cleaner for inground and above ground pools guide.

Why fittings matter

The right adapter ensures a secure connection between the cleaner and the pool system. A loose or mismatched fitting can cause air to enter the suction line, which reduces the cleaner's ability to move. This is not a claim about performance; it is a basic principle of how suction works.

For pressure-side cleaners, a proper fitting prevents water from leaking at the connection point. Again, this is about the physical seal, not the cleaner's cleaning ability. The maker's manual will describe the correct installation. If you are considering a pressure-side cleaner, our pressure-side vs robotic cleaner guide explains the differences.

What to pick for your situation

Questions

What is a skimmer plate adapter?

A skimmer plate adapter is a flat piece that fits over the skimmer opening and has a hole for the cleaner hose. It is commonly included with suction-side cleaners for above ground pools.

Do robotic pool cleaners need adapter fittings?

No. Robotic cleaners are self-contained and connect only to a power source, not to the pool's plumbing. They do not use skimmer plates, unions, or other adapters.

How do you know which adapter fits your pool?

Check the listing for the stated fitting type and size, then compare it with your pool's skimmer or suction line opening. If the listing is unclear, the maker's manual or support page will specify the exact adapter.

What if the listing does not mention an adapter?

If a listing does not state the adapter, it may not be included. Contact the maker or read the manual to see if you need to buy a separate adapter for your pool's connection type.