S300i
Limited evidenceRead the findings →A mid-range corded Dolphin for in-ground pools, with app control and a weekly timer. Owners mostly praise its cleaning, leaves included. Several report costly motor and cable repairs after the warranty, though.
See the alternatives below, or switch market.
Where it sits in Dolphin’s range
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What we know
With no finished independent test yet, the best evidence on the S300i comes from owners: ProductReview.com.au owners lists 34 Australian reviews averaging 3.6 out of 5, and an owner on An owner on Reddit was happy enough in an 18,000-gallon pool to look at another premium Dolphin. Owners broadly agree it cleans well, leaves included. Reliability splits them, with repeated reports of motor and cable failures. Specs come from Maytronics (global).
Owners like the cleaning
Most owners on ProductReview.com.au owners praise it. One with a pool under a neighbour's large eucalypt found it excellent in all modes, another on a leafy acreage chose it for its big basket, and one said it cleared bushfire ash and dust within a few days. An owner on An owner on Reddit with an 18,000-gallon in-ground pool said it worked well. These are owner accounts rather than controlled tests, but they're consistently positive about pickup.
Repairs are the recurring complaint
The negative reviews on ProductReview.com.au owners cluster on reliability. Owners describe motor replacements after two to four years, a power cable that failed a month after the warranty ran out, and a swivel that didn't stop the cable tangling. The owner on An owner on Reddit was shopping because theirs had stopped working, without saying when. That's not a failure rate, but budget for repairs and check your dealer's service record before buying.
App helps, manual steering lags
The MyDolphin Plus app sets a weekly schedule and lets you drive the robot by hand, per Maytronics (global). One owner on ProductReview.com.au owners liked running extra cycles from anywhere, but found the joystick steering so delayed it was useless. Another reported error messages and a schedule that switched itself off after a day or two. Several others never used the app at all and were still happy.
Walls and steps: mostly good
Maytronics lists floor, walls and waterline cleaning with active brushing, per Maytronics (global). Owners on ProductReview.com.au owners mostly agree: one said it does the stairs and walls far better than a suction cleaner, and another saw it scrub tiles well. Not everyone did, though. One owner found it didn't reach the step, and another said it couldn't stay pressed against the waterline tiles. Pool shape may explain the difference.
Our take
Should you buy the S300i?
Best for: In-ground pools whose owners want scheduled cleaning from an app. Skip it if: You need a cleaner that is easy to buy and service locally.
Consider it if you want a Dolphin with app control and a timer for an in-ground pool up to 12 metres, and you buy from a dealer who handles repairs well. Going by owners, budget for repairs after a few years. If you'd rather have test results behind your choice, the Dolphin Nautilus CC Plus has three independent reviews. If you want to lose the cable, look at the Dolphin Liberty 600.
The S300i sits between the basic S200 and the S400 in Dolphin's S-line, sold mainly through pool shops. It plugs into the mains and scrubs the floor, walls and waterline with an active brush, using water jets to grip walls and slopes. The 'i' means Wi-Fi: the MyDolphin Plus app sets schedules and lets you steer it by hand from your phone. It also has a weekly timer, a swivel on its 17-metre cable and a filter basket that lifts out of the top.
The trade-off is longevity. What we know comes from Maytronics and from owners, and those owners mostly like the cleaning, but reports of motor and cable repairs after the warranty come up again and again. Unlike the S400, it has no light to tell you the filter is full.
Before you buy
The questions people ask about this one
Does it climb walls and clean the waterline?
Yes, per the specifications: it cleans the floor, walls and waterline with active brushing. Owners on ProductReview.com.au owners mostly confirm this, but one found it couldn't stay on the waterline tiles and another said it didn't reach the step.
Does it handle leaves as well as fine dirt?
Owners on ProductReview.com.au owners with leafy pools, including gum leaves, pine needles and bushfire ash, mostly say it copes well, and one chose it for its large basket. One unhappy owner found it pushed leaves around instead of collecting them.
How do you clean the filter?
Lift the multi-layer basket out of the top, unsnap the bottom and rinse it, per the specifications. Owners on ProductReview.com.au owners often mention how easy it is to empty. There's no filter-full light, unlike the S400, so check it after each run.
Does it need an app?
No. It has a weekly timer and can be run from its power supply, per the specifications, while the MyDolphin Plus app adds schedules and steering from your phone. Owner reports on ProductReview.com.au owners about the app are mixed, including laggy steering and a schedule that switched itself off.
How long does it last?
Owner reports on ProductReview.com.au owners range from years of trouble-free use to motor replacements after two or three years and cables failing just outside the warranty. Maytronics lists a three-year warranty in Europe, per the specifications. Ask your dealer how repairs are handled before you buy.
Alternatives
Other robotic pool cleaners to compare.
Nautilus CC Plus
Why consider it: Three independent testers found this corded Dolphin cleans floors and walls quickly, with filters that are easy to empty.
The compromise: It sometimes sticks on steps, and testers disagree about whether it cleans the waterline.
LIBERTY 600
Why consider it: Two testers found this cordless Dolphin leaves floors very clean, filters well and comes up when you shake the clicker.
The compromise: It wanders at random, and one tester found its step jet shifted only part of the dirt.
Scuba V3
Why consider it: Its camera steers it towards debris instead of wandering, and three testers praised its pickup.
The compromise: Its runs are shorter, and it sinks again if you miss its 10-minute pickup window.
Specs
Full specifications
Each specification names its source. Manufacturer claims are not independent test results; unconfirmed figures are labelled.
Owner reviews
Do you own the S300i?
Tell people how it’s held up: cleaning, maintenance, faults and support. Owner accounts are shown separately from independent reviews.
Sources
Where this page’s findings come from
Sources
Videos
- Pacific Pool & Spa Gold Coast: Dolphin s300i Robotic Pool Cleaner detailed overview ↗
- Midknight Mechanics: Maytronics Dolphin S300i Robotic Pool Cleaner Unboxing, Use and Review ↗
- Search YouTube for Dolphin S300i ↗Search results may include company demonstrations or similar models. Check the source and model name; a demonstration is not an independent performance test.