Help me choose
Our pick: Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma uses 2 active brushes instead of 1. Dolphin Sigma adds smartphone control.
ProLine
Dolphin Sigma
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
Active
Dolphin Active 20
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 SigmaDolphin Sigma or Dolphin Active 20: our take
Dolphin Sigma and Dolphin Active 20 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
Both robots are intended for inground pools. Both are rated for pools up to 50 ft. Each cleans floor, walls, and waterline, so coverage alone does not separate them. Dolphin Sigma lists 2 active brushes, SmartNav 3.0 with gyroscope navigation, and Triple commercial-grade DC motors. Dolphin Active 20 lists 1 active brush.
Filtration and debris
Dolphin Sigma includes Standard filter and NanoFilters; Dolphin Active 20 includes Basket and UltraFilter. Both have documented fine-debris media, so basket capacity and ease of cleaning matter more than fine-particle capability. Dolphin Active 20 has the better documented path for bulky leaves and larger debris.
Controls and day-to-day ownership
Dolphin Sigma provides a weekly timer, smartphone control, and included remote control; Dolphin Active 20 provides a weekly timer and power-supply controls. Dolphin Sigma uses a 55 ft corded cable with an anti-tangle swivel, while Dolphin Active 20 uses a 60 ft corded cable with an anti-tangle swivel.
Price, warranty and the decision
Dolphin Sigma is listed at $2,399 and Dolphin Active 20 at $1,119; Dolphin Active 20 is $1,280 less. Dolphin Sigma lists a 3-year warranty compared with 2 years for Dolphin Active 20. Pool Express pick: Dolphin Sigma. Dolphin Sigma uses 2 active brushes instead of 1. Dolphin Sigma adds smartphone control. Choose Dolphin Active 20 when it is the better fit for shoppers prioritizing the lower $1,119 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 | Dolphin Sigma | Dolphin Active 20 |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | Yes | Yes |
| Scrubs the waterline | Yes | Yes |
| Fine-debris filter included | Yes | Yes |
| Large-debris filter | No | YesEdge |
| Automatic scheduling | Yes | Yes |
| Smartphone app | YesEdge | No |
| Anti-tangle swivel | Yes | Yes |
| 3-year warranty | YesEdge | No |
| 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 Dolphin Sigma stands out
Dolphin Sigma is the better fit for owners who put smartphone control first.
- Uses 2 active brushes instead of 1
- Adds smartphone control
- Carries a 3-year warranty instead of 2 years
Where Dolphin Active 20 stands out
Dolphin Active 20 is the better fit for shoppers prioritizing the lower $1,119 starting price.
- Includes a large-debris bin or bag for leaves
- Is listed $1,280 lower
Dolphin Sigma vs Dolphin Active 20 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 | Dolphin Sigma | Dolphin Active 20 |
|---|---|---|
| Best fit | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. |
| Starting price | $2,399 | $1,119 |
| Pool type | Inground | Inground |
| Maximum pool length | Up to 50 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor, Walls, Waterline |
| Power | Corded | Corded |
| Filtration | Standard filter, NanoFilters | Basket, UltraFilter |
| Scheduling | Weekly schedule + app | Weekly schedule |
| App and remote | App + included remote | Power-supply controls |
| Cable | 55 ft with anti-tangle swivel | 60 ft with anti-tangle swivel |
| Robot weight | 24.6 lb | Not listed |
| Warranty | 3 years | 2 years |
Choose Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma uses 2 active brushes instead of 1. Dolphin Sigma adds smartphone control.
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