Nobody buys a pool so they can spend Saturday morning pushing a brush around it. An automatic cleaner is the single piece of equipment that buys back the most of your weekend, and it does a more thorough job than most of us do by hand. But walk into the cleaner aisle and you hit a fork in the road immediately: suction-side, pressure-side, or robotic. They all crawl around your pool picking up dirt, yet they work in completely different ways, cost different amounts to run, and shine on different pools.
Pick the wrong type and you will fight it forever — a cleaner that stalls on your steps, misses the leaves, or leans on a pump you do not own. Pick the right one and you basically forget it exists. This guide breaks down how each type works, lays them side by side, and walks you through matching a cleaner to your actual debris, surface, and pool size so you buy once and buy right.
The 60-second version: Want the simplest, most efficient, best-scrubbing option and do not mind a higher sticker price? Buy robotic. Have a lot of big leaves and acorns, an in-ground pool, and a spare return line? A pressure cleaner with its own debris bag is hard to beat. Want the lowest-cost path that uses the pump you already run? A suction cleaner is your friend. The details below tell you which of those three is really you.
The three types, in plain terms
Every automatic cleaner needs energy to move and something to hold the dirt. What separates the three categories is where that energy comes from — your filter pump's suction, a dedicated pressure line, or its own onboard electric motor.
Suction-side cleaners
A suction cleaner plugs into your skimmer or a dedicated suction port and runs entirely on the vacuum your filter pump already makes. It drags a single hose behind it, wandering the floor (and, on better models, the walls) in a semi-random pattern. Whatever it picks up travels down that hose and lands in your pump strainer basket and filter — there is no bag on the cleaner itself. Mechanically they are the simplest of the bunch: usually one moving part, a diaphragm or a turbine, that makes the unit "walk." That simplicity is why they are the least expensive to buy and the easiest to keep alive.
Pressure-side cleaners
A pressure cleaner works in reverse. Instead of sucking water in, it takes pressurized water piped to it and uses that jet to power wheels, a sweep tail, and a venturi that lifts debris up into its own zippered bag. Because the dirt goes into the cleaner's bag and not your filter, your filter stays cleaner and you backwash less often. Most in-ground pressure cleaners need a separate booster pump — a small dedicated pump that gives the cleaner its own high-pressure supply — though some lower-flow models can run off a return line without one. That bag is the pressure cleaner's superpower: it swallows leaves, acorns, and pebbles that would clog a suction unit.
Robotic cleaners
A robot is a self-contained appliance. It does not touch your pump or plumbing at all — it plugs into a standard outlet (through a safe low-voltage transformer) or, on newer cordless models, runs off a rechargeable battery. An internal motor drives the wheels or tracks and pulls water through a built-in filter cartridge or bag, so it scrubs and vacuums independently of your circulation system. Smart navigation maps the pool instead of bouncing around at random, and most units climb the walls and scrub the waterline. They cost the most up front and are the most efficient to run, drawing about as much power as a lightbulb while taking all the load off your filter pump.
Side by side: how the three stack up
Here is the honest comparison. "Upfront cost" is relative between the three categories, not a dollar figure — every model is priced differently and prices move, so check the current price on the product page.
| What matters | Suction-side | Pressure-side | Robotic |
|---|---|---|---|
| How it's powered | Your filter pump's suction | Booster pump or return line | Its own electric motor |
| Where debris goes | Pump basket & filter | Onboard zippered bag | Onboard cartridge or bag |
| Energy to run | None extra (uses existing pump) | Highest (adds a second pump) | Lowest (independent, very efficient) |
| Scrubbing power | Light to moderate | Strong, with a sweep tail | Strongest, active brushes |
| Handles big debris | Poorly — clogs on leaves | Excellent — leaves, acorns, pebbles | Good — depends on the cartridge |
| Climbs walls & waterline | Some models | Floors and lower walls | Yes, most models |
| Load on your filter | High — sends all dirt to it | Low — keeps dirt out of it | None — fully independent |
| Setup & install | Easiest, no new plumbing | Booster pump install if needed | Plug in and drop it in |
| Upfront cost | Lowest | Middle to high | Highest |
| Best fit | Budget-minded, everyday dust & sand | Leafy yards, in-ground pools | Anyone who wants set-and-forget |
Start with your debris, not the marketing
The fastest way to narrow the field is to look at what actually lands in your pool. Cleaners fail when they are asked to eat debris they were never built for.
Fine dust, silt, and sand. If your main problem is a thin gray film on the floor and the odd bit of grit, all three types handle it, so let cost and effort decide. Suction cleaners are genuinely good here because fine dirt passes straight down the hose without clogging. A robot with a fine cartridge gives the cleanest result and polishes the waterline too.
Leaves, twigs, and seed pods. This is where suction cleaners struggle — a single oak leaf can plug the throat and stop the unit dead. Pressure cleaners were made for this. Their large bag and wide intake gulp down leaves and pine needles that would choke anything routed through your pump. A robot with a large-debris bag is the runner-up.
Acorns, pebbles, and heavy grit. Dense debris needs a cleaner that lifts it clear of the mechanism into a bag. Pressure-side is the standout; many models even sweep debris off the walls with their tail. Send acorns through a suction cleaner and you will be clearing jams every few days.
A quick reality check on filters: a suction cleaner routes every speck it collects into your pump basket and filter. On a leafy pool that means emptying baskets and backwashing far more often. Pressure and robotic cleaners keep that debris in their own bag or cartridge, so your filter — and your back — get a break.
Then match it to your pool
Debris tells you what the cleaner needs to eat; your pool tells you what it can physically do.
Above-ground vs. in-ground. Above-ground pools have flat bottoms and no deep-end slope, so a lightweight suction cleaner or a compact robot is ideal. Full-size pressure cleaners with booster pumps are really an in-ground story — they assume a return-line or dedicated plumbing setup you usually will not find on an above-ground pool. If you have an above-ground pool, lean suction or a small dedicated above-ground robot.
Surface. Vinyl liners want soft wheels or tracks and no aggressive scraping — robots and most suction units are gentle here, while a pressure cleaner's wheels are fine as long as the model is rated for vinyl. Gunite and plaster are tougher and pair well with active-scrubbing robots that break up algae film. Fiberglass is slick, so tracked robots grip better than wheels.
Size and shape. On a big pool, random-pattern suction and pressure cleaners can leave patches uncovered on any single run, so they are designed to run long. A robot's smart mapping covers a large pool more completely in a shorter cycle. Lots of steps, benches, and tight corners also favor a robot, which navigates around them instead of getting hung up.
Our picks, one for each type
If you have landed on a category, here is a proven, in-stock model to anchor your search — a mainstream suction unit, a workhorse pressure cleaner, and a cordless robot. Browse the full lineup in the Pool Cleaners collection when you want to compare more options.
Hayward AquaNaut 200 Suction Cleaner
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Polaris 3900 Sport Pressure Cleaner
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Dolphin Liberty 200 Cordless Robotic
Shop NowPrefer to shop by category? Jump straight to Suction Cleaners, Pressure-Side Cleaners, or Robotic Pool Cleaners.
Running cost and what wears out
The sticker price is only half the story. Each type has a different long-term bill.
Suction-side adds nothing to your energy use because it borrows the pump you already run — but it makes that pump work harder and loads your filter, so you may run the pump longer and backwash more. The wear parts are cheap and few: the diaphragm or turbine that makes it walk, the hose sections, and the wear collars. Keeping a spare diaphragm and a hose or two on hand means a five-minute fix instead of a dead cleaner.
Pressure-side carries the highest running cost when it needs a booster pump, because you are now paying to run a second motor during cleaning cycles. The trade is a filter that stays clean and a cleaner that laughs at leaves. Wear items are the debris bag, the tires and the sweep-tail scrubber, and the back-up valve that periodically reverses the unit so it does not get stuck in a corner.
Robotic is the cheapest to run by a wide margin — an efficient low-voltage motor sips power and never touches your pump. Over the years the parts that age are the filter cartridge or bag, the drive brushes, the tracks or wheels, and eventually the power supply or, on cordless models, the battery. Good units are increasingly repairable, so a worn brush set does not mean a new cleaner.
Keep it running: whichever type you choose, a small stash of the model's wear parts turns most breakdowns into a quick swap. You can find diaphragms, bags, tires, hoses, brushes, and back-up valves for all the major brands in our Cleaner Parts & Accessories collection.
Mistakes buyers make
A few traps come up again and again on our support line. Avoid these and you will be happy with almost any well-matched cleaner.
Buying a pressure cleaner without checking the pump situation. Many in-ground pressure models assume a booster pump. If you do not have one, budget for it — or choose a low-flow model rated to run off a return line. Do not discover this after the box is open.
Sending a leafy pool's debris through a suction cleaner. It will clog, and you will spend more time clearing jams than you saved. Heavy leaf load points to pressure or a large-bag robot, full stop.
Ignoring the surface rating. An aggressive cleaner on a delicate vinyl liner, or a wheel design that slips on fiberglass, leads to poor coverage or wear. Confirm the model is rated for your surface before you buy.
Undersizing for the pool. A cleaner built for a 16-by-32 pool will run all day and still miss spots on a big 20-by-40. Match the model's rated pool size to yours, and lean toward a robot's smart coverage on larger or oddly shaped pools.
Forgetting hose or cable length. A suction hose that will not reach the far wall, or a robot cable too short for a long pool, leaves dead zones. Measure the longest diagonal of your pool and make sure the reach covers it.
So which one should you buy?
Strip away the brands and it comes down to three clean answers. If you want the least hassle and the best clean and the price does not scare you, buy a robot — it scrubs hardest, runs cheapest, spares your filter, and needs no plumbing. If your yard drops real leaves and acorns and you have an in-ground pool with a spare line or a booster pump, a pressure cleaner keeps that mess out of your filter and eats debris the others choke on. And if you want automatic cleaning for the smallest outlay, using the pump you already run, a suction cleaner does the everyday job for the least money.
Still torn between two? Let your debris break the tie: fine dirt leans robotic or suction, chunky leaves lean pressure. Then confirm the model fits your surface and pool size, and you are done. When you are ready, compare current models and prices in the Pool Cleaners collection — and if you would like a second opinion on fit for your exact setup, the PST team is a message away.