Hydro 3 vs Hydro 3S

Poolmate Hydro 3 vs Hydro3s: Unboxed, Tested, and Compared

Let’s be honest: nobody actually wants to spend their weekend scrubbing the pool. That’s exactly why robotic pool cleaners exist - and a Poolmate has been making serious waves in this space. Their Hydro line-up has earned a loyal following, and now there are two models sitting side by side: the original Hydro 3 and its upgraded sibling, the Hydro 3S. Both are cordless, both are capable, and both are competing for your money.

So which one do you actually need? We unboxed both, put them through their paces, and broke down exactly where the 3S earns its ”S” - and whether it’s worth the extra spend.

Out of the Box: First Impressions

Both robots arrive in a sturdy Explorer transport case - well-protected and ready for the field. At 7.5kg each, neither unit is going to make your arms ache, and both feature the same ergonomic carry handle that makes getting them poolside genuinely easy. The build quality on both feels solid: IP68-rated waterproof motors, anti-chlorine coatings, and FDA-certified food-grade roller brushes. These are not cheap plastic toys - they’re built for serious, repeated use in harsh pool chemistry.

The first visible difference? Open up the Hydro 3S and you’ll notice the dual-zone filter basket - a new two-compartment design that the standard Hydro 3 doesn’t have. More on why that matters in a moment.

Cleaning Performance: Where Things Get Interesting

The Hydro 3 is no slouch. It boasts a 5,070 GPH dual centrifugal pump system, 98% pool coverage thanks to Anti-Resonance technology, and a 200-minute battery that handles pools up to 1,076 sq. ft. It cleans floors, walls, and waterlines - and its patented waterline lateral scrubbing is genuinely impressive for the price point.

The Hydro 3S takes everything the 3 does and turns it up. Key upgrades are: 

• Dual-zone filtration: The front zone captures leaves and larger debris; the rear zone follows up with five-particle precision, trapping sand and gravel down to 180 microns. It’s a layered cleaning system that the standard Hydro 3 simply can’t match.

• Enhanced waterline coverage: The 3S uses patented lateral jets to tilt its body up to 2 inches, delivering stable wall-climbing with quad-speed active brushes. It scrubs 25% more edge area than the Hydro 3 and handles 0-90° pool wall transitions without breaking a sweat.

• Hydro Curve S navigation: The 3S runs an intelligent S-shaped path that achieves 95% pool coverage with 30% less overlap than random-path cleaning-meaning fewer repeated areas and more of your pool getting attention in every cycle.

• Twice the cleaning efficiency: Poolmate claims the 3S is twice as effective as its predecessor - a bold statement, but one backed up by its 100 gallons per minute suction rate and dual-pump architecture.

Runtime and Battery: How Long Will It Last?

The Hydro 3 runs for up to 200 minutes on a single charge - solid for most home pools. The Hydro3S goes further, offering up to 300 minutes in ECO mode, with a full charge taking around 4 hours. That extra runtime is meaningful if you have a larger pool or simply want to set it going and forget about it for an entire afternoon. Both units feature auto-docking - when the battery runs low or cleaning is complete, the robot makes its own way to the pool edge, ready to be lifted out without you having to fish around the water.

App Control and Smart Features

Both robots connect to the Poolmate Bot app, where you can monitor battery levels, select cleaning modes, and schedule sessions. The Hydro 3S adds weekly timer scheduling, delayed starts, and customisable runtimes - giving you more granular control over exactly when and how your pool gets cleaned. One thing to note: the app connection is Bluetooth only, which means you’ll need the robot out of the water to pair and configure it, as water blocks the signal. It’s a small quirk, but worth knowing before you expect to adjust settings mid-cycle.

Cleaning modes available on the Hydro 3S:

• Auto - full pool clean, floor to waterline

• Pool Floor - targeted floor-only clean

• Walls & Waterline - dedicated wall and edge scrubbing

• ECO Mode - energy-efficient, extended runtime up to 300 minute

Hydro 3 vs Hydro 3S: The Verdict

If you have a smaller pool (under 1000 sq. ft.) and want a capable, reliable, no-fuss robot cleaner, the Hydro 3 delivers excellent value. It cleans thoroughly, handles walls and waterlines well, and the auto-dock feature alone makes it worth the upgrade from manual cleaning.

But if your pool is larger, if you want the smartest navigation available, or if waterline grime is a persistent issue - the Hydro 3S is the clear choice. The dual-zone filtration alone is a genuine step forward, and the extended runtime in ECO mode means it can tackle bigger pools without cutting corners. Independent testing has placed the Hydro 3S in the top three robotic pool cleaners for overall pool coverage and debris pickup, sitting alongside significantly more expensive competitors.

The bottom line: the Hydro 3 is a great robot. The Hydro 3S is a better one.

Watch the Full Unbox and Comparison

Want to see both robots unboxed side by side and put through real pool tests? Watch the full video review on YouTube: (203) Poolmate Hydro 3 vs 3S - Unbox, Review, and Comparison - YouTube