Help me choose
A stronger Pool Express option
Dolphin Premium 40 and Dolphin T55i 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.
Premium
Dolphin Premium 40
Inground pools up to 50 ft that need floor, wall and waterline cleaning with app scheduling and a caddy.
T-Line
Dolphin T55i
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
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 Premium 40 or Dolphin T55i: our take
Dolphin Premium 40 and Dolphin T55i 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 Premium 40'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
Dolphin Premium 40 provides a weekly timer and smartphone control; Dolphin T55i provides a weekly timer, smartphone control, and included remote control. Dolphin Premium 40 uses continuous corded power, while Dolphin T55i uses a 60 ft corded cable with an anti-tangle swivel.
Price, warranty and the decision
Dolphin Premium 40 is listed at $1,629 and Dolphin T55i at $1,699; Dolphin Premium 40 is $70 less. Each lists a 2-year manufacturer warranty. Dolphin Premium 40 and Dolphin T55i 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 Premium 40 | Dolphin T55i |
|---|---|---|
| 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 | Yes | Yes |
| 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 Premium 40 stands out
Dolphin Premium 40 is the better fit for shoppers prioritizing the lower $1,629 starting price.
- Is listed $70 lower
- 2-hour cycle, pools up to 50 ft
Where Dolphin T55i stands out
Dolphin T55i is the better fit for inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
- 60 ft cable with anti-tangle swivel
- Top-load filter basket and ultrafine filters
Dolphin Premium 40 vs Dolphin T55i 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 Premium 40 | Dolphin T55i |
|---|---|---|
| Best fit | Inground pools up to 50 ft that need floor, wall and waterline cleaning with app scheduling and a caddy. | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. |
| Starting price | $1,629 | $1,699 |
| 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 | Basket, UltraFilter | Basket, UltraFilter |
| Scheduling | Weekly schedule + app | Weekly schedule + app |
| App and remote | App control | App + included remote |
| Cable | Not listed | 60 ft with anti-tangle swivel |
| Robot weight | 18.6 lb | Not listed |
| Warranty | 2 years | 2 years |
Consider the stronger Pool Express option
Dolphin Premium 40 and Dolphin T55i 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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