Pick a Pool Cleaner by Pool Type, Size & Surface

Three properties of your pool eliminate most of this market before you look at a single feature list. Apply them in order and the shortlist writes itself.

Gate 1: size, against the published rating

This is the one that cannot be recovered from. Measure your pool’s longest dimension and its floor area, then read what the manufacturer actually publishes — and note that the two conventions in this market are not interchangeable.

• Maytronics (Dolphin) rates by length: 33 ft for the Escape, Cayman and Nautilus AG; 40 ft for the Nautilus CC Plus; 50 ft for the CC Supreme and Wave 60.
• Aiper, Beatbot and WYBOT rate by area: 860 sq ft for the Scuba SE, 1,600 for the Scuba S1 and Seagull Pro, 2,150 for the S1 Pro, 2,152 sq ft per cycle for the WYBOT C2.

A 16 × 32 ft pool is 512 sq ft of floor and roughly 900 sq ft of total wetted surface once you include the walls. So a machine rated 860 sq ft that you also want to climb is already over its rating.

Exceeding the rating does not produce a dramatic failure. The machine simply never finishes — it covers perhaps 70% and parks, and the part it misses is the same part every single cycle. That reads as poor navigation and is actually arithmetic. It is the most common and least recoverable mistake in the category.

Gate 2: shape, which decides whether mapping is worth paying for

A rectangle is kind to pattern navigation: a machine driving parallel lines will cover it. Freeform, kidney, L-shaped, multi-level and beach-entry pools are not, and on those shapes pattern navigation leaves the same regions uncleaned every cycle.

That is where camera mapping earns its price — the Beatbot AquaSense 2 Ultra, the Aiper Scuba V3, the WYBOT S2 Vision. On a plain rectangle it earns nothing, and a $400 pattern-navigating robot covers the floor just as well. This is the single clearest “spend more or spend less” signal in the whole market.

Gate 3: surface, which inverts the answer

Surfaces split into two opposite problems, and advice written for one is wrong for the other.

Rough and abrasive — pebble, exposed aggregate, textured gunite. Grip is excellent, so climbing is easy. But the surface is effectively sandpaper: brushes wear in about a season rather than two or three, and grit works into the drivetrain. Here brush price and availability matter more than any headline spec, which is why the pebble roundup leans Maytronics and Hayward — and why a suction cleaner with no brushes to destroy stays genuinely competitive.

Smooth and slick — fiberglass gelcoat above all, and newer vinyl liner. Brushes last two or three seasons, but climbing fails because there is nothing to bite. Tracked drives with defined tread hold where wheels spin, which is why the fiberglass roundup ranks on track grip. Gelcoat also shows fine sediment that would be invisible on pebble, so fine filtration matters more here.

Vinyl liner carries its own constraint: a liner is a $4,000-6,000 consumable, and brush compound is a real risk rather than a theoretical one. The liner page covers it, and it is why Maytronics’ above-ground machine deliberately does not climb.

Gate 4: power architecture, which follows from size

Over about 2,200 sq ft, cordless becomes awkward — even the longest-running battery machine has to charge mid-job, and the half it does second is always the same half. Corded has no runtime limit at all.

Under 2,200 sq ft the choice stops being about whether the machine can finish and becomes about how long you want it to last: cordless gives you the better current specification, corded gives you no battery to age.

The three things pool owners consistently underestimate

• Weight. You lift this out of the water twice a week, often over coping or a pool wall. A 29 lb flagship and a 15 lb budget machine are different purchases, and the heavy one gets used less. Budget for a caddy over about 20 lb.
• Fixtures. Main drains, step returns, benches and tanning ledges strand robots. A machine that strands in a 400 sq ft pool has lost a quarter of its coverage, which is why “high obstacle crossing” and platform modes are real specs rather than marketing.
• Consumables. Brushes, tracks and filters are the annual cost, and they vary by a factor of four between brands. Filters by brand puts every price side by side.

Above-ground and soft-sided pools are a different problem

Worth separating, because most reviews just rank inground machines and note which ones “also work” above ground. An above-ground pool has a flat floor, a tight radius cove where debris collects, a thin liner wall you should not scrub hard, and a four-foot wall you lift the machine over. A soft-sided pool adds a floor that flexes under the machine’s weight and a wall that deflects so climbing physically cannot work.

Those are genuinely different requirements, and the above-ground page and the Intex page are written to them rather than adapted from an inground list.