Help me choose
A stronger Pool Express option
Dolphin S400 and Niya Tracker 15 are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Cayman. Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
S-Line
Dolphin S400
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
Niya Tracker
Niya Tracker 15
Above-ground pools up to 20 ft that need the floor vacuumed without a cord.
What we recommend instead
Dolphin Cayman
Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
$1,079
Buy Dolphin CaymanDolphin S400 or Niya Tracker 15: our take
Dolphin S400 and Niya Tracker 15 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
Dolphin S400 is intended for inground pools, while Niya Tracker 15 is intended for above-ground pools. Dolphin S400 is rated for pools up to 50 ft; Niya Tracker 15 is rated up to 20 ft. Dolphin S400 cleans floor, walls, and waterline; Niya Tracker 15 cleans floor. Dolphin S400's documented cleaning system includes 2 active brushes and CleverClean navigation.
Filtration and debris
Dolphin S400 includes Basket and UltraFilter; Niya Tracker 15 includes Basket. That gives Dolphin S400 the clearer documented edge for fine silt, pollen and sand.
Controls and day-to-day ownership
Dolphin S400 provides a weekly timer and smartphone control; Niya Tracker 15 provides one-touch starts and power-supply controls. Dolphin S400 uses a 60 ft corded cable with an anti-tangle swivel, while Niya Tracker 15 uses cordless battery power.
Price, warranty and the decision
Dolphin S400 is listed at $1,799 and Niya Tracker 15 at $199; Niya Tracker 15 is $1,600 less. Dolphin S400 lists a 2-year warranty compared with 1 years for Niya Tracker 15. Dolphin S400 and Niya Tracker 15 each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Dolphin Cayman. Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
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 S400 | Niya Tracker 15 |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | YesEdge | No |
| Scrubs the waterline | YesEdge | No |
| Fine-debris filter included | YesEdge | No |
| Large-debris filter | Yes | Yes |
| Automatic scheduling | YesEdge | No |
| Smartphone app | YesEdge | No |
| Anti-tangle swivel | Yes | Not listed |
| 3-year warranty | No | No |
| No recharging between cycles | YesEdge | No |
| 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 S400 stands out
Dolphin S400 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
- Can start on a weekly schedule without a manual launch before every cycle
- Adds smartphone control
Where Niya Tracker 15 stands out
Niya Tracker 15 is the better fit for shoppers prioritizing the lower $199 starting price.
- Is listed $1,600 lower
- Cleans the pool floor
Dolphin S400 vs Niya Tracker 15 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 S400 | Niya Tracker 15 |
|---|---|---|
| Best fit | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. | Above-ground pools up to 20 ft that need the floor vacuumed without a cord. |
| Starting price | $1,799 | $199 |
| Pool type | Inground | Above-ground |
| Maximum pool length | Up to 50 ft | Up to 20 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor |
| Power | Corded | Cordless |
| Filtration | Basket, UltraFilter | Basket |
| Scheduling | Weekly schedule + app | One-touch start |
| App and remote | App control | Power-supply controls |
| Cable | 60 ft with anti-tangle swivel | Cordless |
| Robot weight | Not listed | 7.1 lb |
| Warranty | 2 years | 1 years |
Consider the stronger Pool Express option
Dolphin S400 and Niya Tracker 15 are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Cayman. Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
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