Help me choose
A stronger Pool Express option
Dolphin Liberty 600 and Dolphin M550 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.
Liberty
Dolphin Liberty 600
Inground and above-ground pools up to 50 ft that need floor, wall, waterline and lounge-area cleaning without a cord.
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.
What we recommend instead
Dolphin Quantum
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
$1,649
Buy Dolphin QuantumDolphin Liberty 600 or Dolphin M550: our take
Dolphin Liberty 600 and Dolphin M550 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 Liberty 600 is intended for inground and above-ground pools, while Dolphin M550 is 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 M550's documented cleaning system includes 2 active brushes and CleverClean navigation.
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
Both models provide a weekly timer and smartphone control. Dolphin Liberty 600 uses cordless battery power, while Dolphin M550 uses continuous corded power. Dolphin Liberty 600 is listed at 25.8 lb versus 22.6 lb for Dolphin M550; that 3.1999999999999993 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Dolphin Liberty 600 is listed at $1,729 and Dolphin M550 at $1,999; Dolphin Liberty 600 is $270 less. Each lists a 3-year manufacturer warranty. Dolphin Liberty 600 and Dolphin M550 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 Liberty 600 | Dolphin M550 |
|---|---|---|
| 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 | Yes | Yes |
| Automatic scheduling | Yes | Yes |
| Smartphone app | Yes | Yes |
| Anti-tangle swivel | Not listed | Yes |
| 3-year warranty | Yes | Yes |
| No recharging between cycles | No | YesEdge |
| 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 Liberty 600 stands out
Dolphin Liberty 600 is the better fit for shoppers prioritizing the lower $1,729 starting price.
- Is listed $270 lower
- Cleans floor, walls, waterline and lounge areas
Where Dolphin M550 stands out
Dolphin M550 is the better fit for inground pools up to 50 ft that need floor, wall and waterline cleaning with app control, Pick-Up and a caddy.
- Runs from continuous plug-in power without a recharge between cycles
- Weighs 22.6 lb versus 25.8 lb
Dolphin Liberty 600 vs Dolphin M550 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 Liberty 600 | Dolphin M550 |
|---|---|---|
| Best fit | Inground and above-ground pools up to 50 ft that need floor, wall, waterline and lounge-area cleaning without a cord. | Inground pools up to 50 ft that need floor, wall and waterline cleaning with app control, Pick-Up and a caddy. |
| Starting price | $1,729 | $1,999 |
| Pool type | Inground, Above-ground | Inground |
| Maximum pool length | Up to 50 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor, Walls, Waterline |
| Power | Cordless | Corded |
| Filtration | Basket, UltraFilter | Basket, UltraFilter |
| Scheduling | Weekly schedule + app | Weekly schedule + app |
| App and remote | App control | App control |
| Cable | Cordless | Not listed |
| Robot weight | 25.8 lb | 22.6 lb |
| Warranty | 3 years | 3 years |
Consider the stronger Pool Express option
Dolphin Liberty 600 and Dolphin M550 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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