Help me choose
A stronger Pool Express option
Aquabot X2 and Dolphin M400 are compared feature by feature below. For a stronger Pool Express option, consider Clear S. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
Aquabot
Aquabot X2
Inground and above-ground pools up to 40 ft that need floor cleaning.
M-Line
Dolphin M400
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
What we recommend instead
Clear S
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
$1,749
Buy Clear SAquabot X2 or Dolphin M400: our take
Aquabot X2 and Dolphin M400 are compared on pool fit, cleaning reach, debris handling, controls and ownership details. The recommendation is based on the job the robot must do—not a simple feature count.
Pool fit and cleaning reach
Aquabot X2 is intended for inground and above-ground pools, while Dolphin M400 is intended for inground pools. Aquabot X2 is rated for pools up to 40 ft; Dolphin M400 is rated up to 50 ft. Aquabot X2 cleans floor; Dolphin M400 cleans floor, walls, and waterline. Aquabot X2's documented cleaning system includes 1 active brush.
Filtration and debris
Dolphin M400 has documented included filtration—Standard filter and UltraFilter—while the other model's included media is not fully published. Dolphin M400 has the clearer documented edge for fine silt, pollen and sand.
Controls and day-to-day ownership
Aquabot X2 provides no fully published timer, app or remote specification; Dolphin M400 provides smartphone control.
Price, warranty and the decision
Aquabot X2 is listed at $497 and Dolphin M400 at $1,599; Aquabot X2 is $1,102 less. Aquabot X2 lists a 2-year warranty compared with 3 years for Dolphin M400. Aquabot X2 and Dolphin M400 each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Clear S. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
Feature check: what each robot actually has
A green check means the feature is documented as included. A red X means it is documented as absent. A dash means the source does not make the feature clear.
| Feature | Aquabot X2 | Dolphin M400 |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | No | YesEdge |
| Scrubs the waterline | No | YesEdge |
| Fine-debris filter included | No | YesEdge |
| Large-debris filter | No | No |
| Automatic scheduling | Not listed | Not listed |
| Smartphone app | Not listed | Yes |
| Anti-tangle swivel | Not listed | Yes |
| 3-year warranty | No | YesEdge |
| No recharging between cycles | Not listed | Yes |
| Built-in UV-C water treatment | No | No |
Unknown is not treated as “no.” Specifications come from the product pages, current catalog records and manufacturer material collected for this site.
Where Aquabot X2 stands out
Aquabot X2 is the better fit for shoppers prioritizing the lower $497 starting price.
- Is listed $1,102 lower
- Cleans the pool floor
Where Dolphin M400 stands out
Dolphin M400 is the better fit for pools up to 50 ft.
- Cleans the floor, walls and waterline instead of stopping below the tile line
- Includes filtration for sand, pollen and other fine debris
- Has documented smartphone control
- Carries a 3-year warranty instead of 2 years
Aquabot X2 vs Dolphin M400 specifications
Use pool fit first. Price and app control do not make up for a robot that cannot cover the length or surfaces you need cleaned.
| Specification | Aquabot X2 | Dolphin M400 |
|---|---|---|
| Best fit | Inground and above-ground pools up to 40 ft that need floor cleaning. | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. |
| Starting price | $497 | $1,599 |
| Pool type | Inground, Above-ground | Inground |
| Maximum pool length | Up to 40 ft | Up to 50 ft |
| Cleaning coverage | Floor | Floor, Walls, Waterline |
| Power | Not listed | Corded |
| Filtration | Not listed | Standard filter, UltraFilter |
| Scheduling | Not listed | Not listed |
| App and remote | Not listed | App control |
| Cable | Not listed | 60 ft with anti-tangle swivel |
| Robot weight | Not listed | Not listed |
| Warranty | 2 years | 3 years |
Consider the stronger Pool Express option
Aquabot X2 and Dolphin M400 are compared feature by feature below. For a stronger Pool Express option, consider Clear S. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
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