Robotic pool cleaner comparison

Dolphin M550 vs Dolphin T25

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 M550 and Dolphin T25 are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Quantum. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.

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M-Line

Dolphin M550

Inground pools up to 50 ft that need floor, wall and waterline cleaning with app control, Pick-Up and a caddy.

Listed price $1,999

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T-Line

Dolphin T25

Inground and above-ground pools up to 33 ft that need floor and wall cleaning, with fine debris.

Listed price $849

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A better alternative

What we recommend instead

Pool Express pick

Dolphin Quantum

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

$1,649

Buy Dolphin Quantum

Buying guidance

Dolphin M550 or Dolphin T25: our take

Dolphin M550 and Dolphin T25 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 M550 is intended for inground pools, while Dolphin T25 is intended for inground and above-ground pools. Dolphin M550 is rated for pools up to 50 ft; Dolphin T25 is rated up to 33 ft. Dolphin M550 cleans floor, walls, and waterline; Dolphin T25 cleans floor and walls. Dolphin M550 lists 2 active brushes and CleverClean navigation. Dolphin T25 lists 1 active brush.

Filtration and debris

Both models include Basket and UltraFilter. Both have documented fine-debris media, so basket capacity and ease of cleaning matter more than fine-particle capability.

Controls and day-to-day ownership

Dolphin M550 provides a weekly timer and smartphone control; Dolphin T25 provides a weekly timer and power-supply controls. Dolphin M550 uses continuous corded power, while Dolphin T25 uses a 50 ft corded cable. Dolphin M550 is listed at 22.6 lb versus 15 lb for Dolphin T25; that 7.600000000000001 lb difference matters when lifting the robot from the pool.

Price, warranty and the decision

Dolphin M550 is listed at $1,999 and Dolphin T25 at $849; Dolphin T25 is $1,150 less. Dolphin M550 lists a 3-year warranty compared with 2 years for Dolphin T25. Dolphin M550 and Dolphin T25 each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Dolphin Quantum. 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	Dolphin M550	Dolphin T25
Cleans the pool floor	Yes	Yes
Climbs and cleans walls	Yes	Yes
Scrubs the waterline	YesEdge	No
Fine-debris filter included	Yes	Yes
Large-debris filter	Yes	Yes
Automatic scheduling	Yes	Yes
Smartphone app	YesEdge	No
Anti-tangle swivel	Yes	Not listed
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 M550 stands out

Dolphin M550 is the better fit for pools up to 50 ft.

Cleans the floor, walls and waterline instead of stopping below the tile line
Uses 2 active brushes instead of 1
Adds smartphone control
Carries a 3-year warranty instead of 2 years

Where Dolphin T25 stands out

Dolphin T25 is the better fit for shoppers prioritizing the lower $849 starting price.

Is listed $1,150 lower
Weighs 15 lb versus 22.6 lb