Help me choose
Our pick: Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma includes filtration for sand, pollen and other fine debris. Dolphin Sigma uses 2 active brushes instead of 1.
Aquabot
Aquabot X4
Inground and above-ground pools up to 60 ft that need floor, wall and waterline cleaning.
ProLine
Dolphin Sigma
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
Why Dolphin Sigma is our pick
Dolphin Sigma
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
$2,399
Buy Dolphin SigmaAquabot X4 or Dolphin Sigma: our take
Aquabot X4 and Dolphin Sigma 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 X4 is intended for inground and above-ground pools, while Dolphin Sigma is intended for inground pools. Aquabot X4 is rated for pools up to 60 ft; Dolphin Sigma is rated up to 50 ft. Each cleans floor, walls, and waterline, so coverage alone does not separate them. Aquabot X4 lists 1 active brush and Intelligent navigation. Dolphin Sigma lists 2 active brushes, SmartNav 3.0 with gyroscope navigation, and Triple commercial-grade DC motors.
Filtration and debris
Aquabot X4 includes Basket; Dolphin Sigma includes Standard filter and NanoFilters. Dolphin Sigma has the clearer documented edge for fine silt, pollen and sand. Aquabot X4 also has the better documented path for bulky leaves and larger debris.
Controls and day-to-day ownership
Aquabot X4 provides a weekly timer; Dolphin Sigma provides a weekly timer, smartphone control, and included remote control. Aquabot X4 uses a 60 ft corded cable with an anti-tangle swivel, while Dolphin Sigma uses a 55 ft corded cable with an anti-tangle swivel. Aquabot X4 is listed at 40 lb versus 24.6 lb for Dolphin Sigma; that 15.399999999999999 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Aquabot X4 is listed at $747 and Dolphin Sigma at $2,399; Aquabot X4 is $1,652 less. Aquabot X4 lists a 2-year warranty compared with 3 years for Dolphin Sigma. Pool Express pick: Dolphin Sigma. Dolphin Sigma includes filtration for sand, pollen and other fine debris. Dolphin Sigma uses 2 active brushes instead of 1. Choose Aquabot X4 when it is the better fit for shoppers prioritizing the lower $747 starting price.
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 X4 | Dolphin Sigma |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | Yes | Yes |
| Scrubs the waterline | Yes | Yes |
| Fine-debris filter included | No | YesEdge |
| Large-debris filter | YesEdge | No |
| Automatic scheduling | Yes | Yes |
| Smartphone app | Not listed | Yes |
| Anti-tangle swivel | Yes | Yes |
| 3-year warranty | No | YesEdge |
| No recharging between cycles | Yes | 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 X4 stands out
Aquabot X4 is the better fit for shoppers prioritizing the lower $747 starting price.
- Includes a large-debris bin or bag for leaves
- Is rated for pools up to 60 ft
- Is listed $1,652 lower
Where Dolphin Sigma stands out
Dolphin Sigma is the better fit for inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
- Includes filtration for sand, pollen and other fine debris
- Uses 2 active brushes instead of 1
- Adds gyroscope-assisted navigation
- Has documented smartphone control
Aquabot X4 vs Dolphin Sigma 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 X4 | Dolphin Sigma |
|---|---|---|
| Best fit | Inground and above-ground pools up to 60 ft that need floor, wall and waterline cleaning. | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. |
| Starting price | $747 | $2,399 |
| Pool type | Inground, Above-ground | Inground |
| Maximum pool length | Up to 60 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor, Walls, Waterline |
| Power | Corded | Corded |
| Filtration | Basket | Standard filter, NanoFilters |
| Scheduling | Weekly schedule | Weekly schedule + app |
| App and remote | Not listed | App + included remote |
| Cable | 60 ft with anti-tangle swivel | 55 ft with anti-tangle swivel |
| Robot weight | 40 lb | 24.6 lb |
| Warranty | 2 years | 3 years |
Choose Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma includes filtration for sand, pollen and other fine debris. Dolphin Sigma uses 2 active brushes instead of 1.
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