Robotic pool cleaner comparison

Dolphin S300 vs Dolphin T15

A side-by-side comparison of pool fit, cleaning coverage, filtration, controls and the better Pool Express option.

By Brian Williamson, Pool Express product specialist
Updated November 9, 2026

Better alternative

A stronger Pool Express option

Dolphin S300 and Dolphin T15 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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S-Line

Dolphin S300

Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.

Listed price $1,499

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T-Line

Dolphin T15

Above-ground pools up to 30 ft that need floor cleaning.

Listed price $649

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A better alternative

What we recommend instead

Pool Express pick

Dolphin Cayman

Inground and above-ground pools up to 40 ft that need floor and wall cleaning.

$1,079

Buy Dolphin Cayman

Buying guidance

Dolphin S300 or Dolphin T15: our take

Dolphin S300 and Dolphin T15 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 S300 is intended for inground pools, while Dolphin T15 is intended for above-ground pools. Dolphin S300 is rated for pools up to 50 ft; Dolphin T15 is rated up to 30 ft. Dolphin S300 cleans floor, walls, and waterline; Dolphin T15 cleans floor. Dolphin S300 lists 2 active brushes and CleverClean navigation. Dolphin T15 lists 1 active brush.

Filtration and debris

Dolphin S300 includes Basket and UltraFilter; Dolphin T15 includes Basket. That gives Dolphin S300 the clearer documented edge for fine silt, pollen and sand.

Controls and day-to-day ownership

Dolphin S300 provides a weekly timer and smartphone control; Dolphin T15 provides one-touch starts and power-supply controls. Dolphin S300 uses a 60 ft corded cable with an anti-tangle swivel, while Dolphin T15 uses a 40 ft corded cable.

Price, warranty and the decision

Dolphin S300 is listed at $1,499 and Dolphin T15 at $649; Dolphin T15 is $850 less. Each lists a 2-year manufacturer warranty. Dolphin S300 and Dolphin T15 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 S300	Dolphin T15
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	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 S300 stands out

Dolphin S300 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
Uses 2 active brushes instead of 1
Can start on a weekly schedule without a manual launch before every cycle

Where Dolphin T15 stands out

Dolphin T15 is the better fit for shoppers prioritizing the lower $649 starting price.

Is listed $850 lower
Cleans the pool floor