Quick verdict
The premium corded pick for app-era owners. If you want top-tier Dolphin cleaning and never want to think about a battery, this is it.
Ideal for
- In-ground pools up to 50 ft
- Owners who want app scheduling without battery ownership
- Fine-dust pools (ultra-fine filter kit included)
Not ideal for
- Cable haters — go Liberty 600 or cordless rivals
- Surface-debris problems
- Budget buyers
The full picture
The Sigma is Maytronics' premium corded answer for owners unmoved by the cordless trend: floor, wall, and waterline coverage for pools up to 50 feet, a 2.5-hour cycle, MyDolphin Plus app support, weekly timer, anti-tangle swivel, fine plus ultra-fine filter kits, and a 3-year warranty, at about 24.6 lb. No charging, no battery replacement down the road, no runtime anxiety — plug it in and schedule the week. Owner feedback mirrors the corded premium tier generally: excellent cleaning consistency, with cable management the only recurring gripe.
Dolphin Sigma at a glance
- Cleaning coverage
- Floor + walls + waterline
- Pool type
- In-ground
- Max pool size (ft)
- 50
- Cordless
- No
- Weight (lb)
- 24.6
- Wall climbing
- Yes
- Waterline cleaning
- Yes
- Filtration
- Fine + ultra-fine filter kits
- App control
- Yes
- Weekly timer
- Yes
Source: Compiled from Maytronics product documentation, published specifications, and aggregated verified-owner feedback.
This is a research-based review — our analysis draws on manufacturer specifications, manuals, warranty terms, and verified owner feedback rather than our own hands-on testing, and we note where a detail couldn't be confirmed. How we review
The in-depth review
The Sigma is the premium corded Dolphin for the app era — top-tier cleaning and phone scheduling, with no battery to ever charge, degrade, or replace.
Premium cleaning, no battery
It covers floor, walls, and waterline on pools up to 50 feet, and the MyDolphin Plus app adds weekly scheduling and control. Ultra-fine filtration comes included, so fine dust and silt get caught rather than recirculated. Because it's corded, there's nothing to recharge and no battery life to worry about years down the road — a real advantage if you plan to keep the robot a long time.
The trade-offs
The flip side of corded is the cable: even with the anti-tangle swivel, you're still managing it, especially in a freeform pool. There's no surface skimming, and it's heavier than compact corded models.
Performance breakdown
Research-based editorial judgments from specs, warranty terms, and verified owner feedback — not lab measurements. How we score
Pros and cons
What works
- Ultra-fine filtration included
- MyDolphin Plus app with weekly scheduling
- No battery to charge, degrade, or replace
- 3-year warranty + Maytronics network
What doesn't
- Cable management, even with the swivel
- No surface skimming
- Heavier than compact corded models
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Frequently asked questions
Is the Dolphin Sigma cordless or corded?
The Dolphin Sigma is corded — it runs on continuous mains power through a floating cable, so there is no battery to recharge between cycles.
What does the Dolphin Sigma clean?
The Dolphin Sigma is rated to clean the floor, walls and waterline. That includes the waterline, where sunscreen and body oils build into a greasy ring. It is an underwater cleaner, so it does not skim floating debris off the surface.
What size pool is the Dolphin Sigma designed for?
It is rated for pools up to 50 feet. On a longer pool it covers less ground per cycle and can miss spots, so size up if your pool runs past that.
Does the Dolphin Sigma have app control?
Yes — the Dolphin Sigma pairs with a mobile app, and it supports scheduling.
What filtration does the Dolphin Sigma use?
It filters debris through a fine and ultra-fine filter kits. Rinse it after each cycle so suction and pickup stay strong.
What warranty does the Dolphin Sigma come with?
It comes with a 3-year limited manufacturer warranty (confirm current terms at purchase).