Maytronics US Inc. (Dolphin Pool Cleaners) 99991053-USI M400 Deluxe Robotic Pool Cleaner
99991053-USI
Dolphin M400 Deluxe (99991053-USI) at a glance
The M400 is Maytronics' heavy-duty corded Dolphin for deeper, larger in-ground pools up to 50 feet. Three brushes, strong 4,500 gph suction and a heavier build keep it on the floor and walls of deep ends, and the MyDolphin Plus app adds a weekly timer and spot cleaning. Because it plugs in, there's no battery to charge.
- Coverage: floor, walls and waterline, with three brushes and waterline scrubbing
- Cycle: 2.5 hr default
- Suction: 4,500 gallons per hour
- Power: plug-in power supply; no battery, no charging
- Cable: floating cable with an anti-tangle swivel
- App: MyDolphin Plus over Wi-Fi: start/stop, weekly timer and spot cleaning
- Filtration: top-access fine filter kit, plus an ultra-fine kit in the box
- Pool size: in-ground pools up to 50 ft long
- Caddy: included
- Warranty: 3-year limited (Maytronics)
Our pairing pick: add a Betta SE Plus solar skimmer
Most of what ends up on your pool floor starts out floating: leaves, pollen, bugs and dust. The Betta SE Plus solar robotic skimmer patrols the surface all day on solar power and catches that debris before it sinks. With the surface handled, the M400 has less to pick up, its filter fills more slowly, and you won't need to run it as often. The Betta has no cord, so there's nothing for the Dolphin's floating cable to tangle with.
See it in action
Maytronics overview
Unboxing (Maytronics)
Using it: what to expect
Corded robots like the M400 don't have the charging limits of a cordless robot. You can run a cycle, rinse the filter and start another right away. A few things still matter:
| Situation | What to plan for |
|---|---|
| Normal weekly upkeep | Set the weekly timer in the MyDolphin Plus app and let it run on its own, or start cycles when you need them. The 2.5-hour default suits most pools. |
| Spring opening / pool closed all winter | Net out the big leaves first and get the water clear. A winter's worth of debris fills the filter quickly, and a full filter cuts suction and climbing. Use the fine filter for heavy debris, rinse it between cycles, and run as many cycles as it takes. Because it's corded, you can run them back to back. |
| Fine dust, pollen, silt | Switch to the included ultra-fine kit once the heavy debris is gone. |
| Cable tangles | The swivel cuts down on twisting. Lay the cable out straight with no coils. If it does twist, unplug it and work the twists out starting at the robot end. |
| Getting it out | The M400 weighs about 27 lb, more than most robots, so lift it by the handle (never the cable) and let the water drain at the waterline before hauling it out. |
| Where the power supply goes | Away from the pool edge, plugged straight into a GFCI outlet (no extension cord). Keep it out of direct sun and rain. |
| Storage | Rinse the filter, untangle and loosely coil the cable, and park the robot on its caddy out of direct sun between uses. Over a Minnesota winter, store the robot, cable and power supply indoors where they won't freeze. |
Cleaning cycles
The default cycle is 2.5 hours and covers the floor, walls and waterline. Set the weekly timer, start cycles and steer spot cleaning in the MyDolphin Plus app. The M400 has no delayed start.
Dolphin S2000 vs S3000 vs M400
| Feature | S2000 | S3000 Deluxe | M400 Deluxe (this model) |
|---|---|---|---|
| Max pool length | 40 ft | 50 ft | 50 ft |
| Coverage | Floor, walls, waterline, steps, sun ledges | Floor, walls, waterline, steps, sun ledges | Floor, walls, waterline |
| Default cycle | 2.5 hr | 2.5 hr | 2.5 hr |
| Filtration | Combined filter + ultra-fine kit | Multi-layer + ultra-fine kit | Fine filter + ultra-fine kit |
| Swivel | Yes | Yes | Yes |
| App (MyDolphin Plus) | Yes | Yes | Yes |
| Weekly timer | Yes | Yes | Yes |
| Caddy | Not included | Included | Included |
| Brushes | 2 | — | 3 |
| Warranty | 2 years | 3 years | 3 years |
See all our robotic pool cleaners →
Specifications
| Part number | 99991053-USI (Maytronics Dolphin M400) |
| UPC | 810071222016 |
| Pool type | In-ground; rectangular, round, free-form, kidney |
| Pool size | Up to 50 ft long |
| Coverage | Floor, walls, waterline |
| Brushes | Three (standard and combination), active brushing |
| Default cycle | 2.5 hours |
| Suction | 4,500 gph |
| Filtration | Top-access fine filter kit; ultra-fine kit included |
| Cable | Floating cable with anti-tangle swivel |
| App | MyDolphin Plus (Wi-Fi) |
| Scheduling | Weekly timer (no delayed start) |
| Robot weight | About 27 lb |
| Robot dimensions | About 16.8 × 16.2 × 10.7 in (L × W × H) |
| Caddy | Included |
| Warranty | 3-year limited |
What's in the box
- Dolphin M400 robotic cleaner with floating swivel cable
- Wi-Fi power supply
- Fine filter kit, plus an ultra-fine filter kit
- Caddy
Care
- Rinse the filter after every cycle, before debris dries on it.
- Swap between fine and ultra-fine filters as the season changes.
- Take the cleaner out of the pool during shock treatments.
Common questions
Do I need to charge it?
No. The M400 is corded, so it runs whenever it's plugged in. You can run cycles back to back.
Can it clean on a schedule?
Yes. Set the weekly timer in the MyDolphin Plus app.
Is it good for deep pools?
Yes. Maytronics positions the M400 for deeper pools; its weight, three brushes and 4,500 gph suction keep it working the deep end and walls.
M400 or S3000?
Both handle pools up to 50 ft with a caddy and 3-year warranty. The M400 brings a third brush and a heavier build for deep pools; the S3000 adds step and sun-ledge cleaning, a multi-layer filter and delayed start.
Will it work in an above-ground pool?
No. Maytronics rates the M400 for in-ground pools.
Also searched as: Dolphin M400, Maytronics M400 Deluxe, 99991053, Dolphin M 400 robotic pool cleaner for deep pools, corded robot pool vacuum.
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