There’s a specific kind of morning routine for pool owners that involves a cup of coffee, a long pole, and a fair amount of sighing while staring at the “scum line” on the tiles. After years of being my own pool boy, I finally decided to let the robots take over. I’ve spent the last several months alternating between the Dolphin Proteus DX3 and its bigger, more aggressive brother, the Dolphin Proteus DX4.
Both machines arrive with a certain pedigree—Maytronics has been doing this for over 40 years—but they treat your pool very differently. One is a light, nimble floor-and-wall specialist, while the other is a heavyweight designed to attack the hardest part of the pool to clean: the waterline. If you’re standing in a pool store (or browsing online) wondering why the DX4 carries a higher price tag for what looks like the same plastic shell, I’ve got the answer. After 60 days of “robot wrestling” in my own backyard, here is my take on which one actually deserves a spot on your pool deck.
The Key Difference: Waterline Scrubbing and Anti-Tangle Tech
The primary difference between the Dolphin Proteus DX3 and the Proteus DX4 is the cleaning reach and cable management. The DX3 is built for pools up to 33 feet and focuses on scrubbing the floor and walls, but it lacks an anti-tangle swivel.
The DX4, however, is rated for larger pools up to 50 feet, includes a 60-foot cable with a patented anti-tangle swivel, and features PowerStream technology for dedicated waterline scrubbing. While both come with a caddy in these specific bundles, the DX4 is a significantly more “autonomous” machine thanks to its ability to prevent cord knots and scrub the tile line.
- WALL-SCRUBBING POWER: Dolphin Proteus DX3 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin Proteus DX3 - active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle...
- WALL-SCRUBBING POWER: Dolphin Proteus DX4 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin's active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle on surfaces,...
Comparison Table: Dolphin Proteus DX3 vs. DX4
| Feature | Dolphin Proteus DX3 | Dolphin Proteus DX4 |
| Max Pool Size | Up to 33 Feet | Up to 50 Feet |
| Cleaning Coverage | Floor and Walls | Floor, Walls, & Waterline |
| Cable Length | 50 Feet | 60 Feet |
| Anti-Tangle Swivel | No | Yes (360 Degree) |
| Mobility System | Standard Tracks | PowerStream (Multi-Directional) |
| Caddy Included | Yes (Bundle Model) | Yes (Bundle Model) |
| Brushing | Single Active Scrubber | Dual Active Scrubbers (Front/Rear) |
| Warranty | 2-Year Limited | 2-Year Limited |
| Buy NOW | Buy on Amazon | Buy on Amazon |
Detailed Comparative Review: My Experience on the Deck
To give you the full picture, I’ve broken down my experience into the four categories that actually matter once the robot is out of the box.
Design: The Compact Sprinter vs. The All-Surface Tank
When I first unboxed the Proteus DX3, I loved how light it felt. It’s a “white-and-blue” machine that is incredibly easy to lift. Because it’s smaller, it handles tight corners and swim-outs with surprising speed. However, I noticed it only has one active scrubbing brush at the front.
The Proteus DX4 feels more “complete.” It’s slightly heavier, but it utilizes Dual Active Scrubbing. It has brushes at both the front and the back, which I found made a huge difference when dealing with stuck-on pollen or those stubborn algae spots that start to form in the deep end. The DX4 also uses PowerStream technology, which looks like little water jets on the side. These jets allow it to “sidestep” along the waterline, a move the DX3 simply cannot perform.
- WALL-SCRUBBING POWER: Dolphin Proteus DX3 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin Proteus DX3 - active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle...
Ease of Use: The “Tangle” Factor
I’ll be honest: I didn’t think the anti-tangle swivel was a big deal until I used the DX3 for a week. Without a swivel, the DX3’s 50-foot cord eventually starts to look like a telephone cord from 1995—coiled and knotted. Every three or four cycles, I had to physically stretch the cord out on the lawn to untwist it.
The DX4 solves this entirely. Its 360-degree swivel allows the robot to spin and turn as much as it wants without tangling the “leash.” In terms of daily use, this means I can leave the DX4 in the pool for its weekly schedule without worrying that it will get stuck in a corner because the cord is too knotted to move. Both units come with a Universal Caddy, which is a godsend for transporting them to the garage, but the DX4’s cable management makes it the clear winner for “set-and-forget” owners.
Functions: Waterline vs. Wall Climbing
This is the “make or break” feature. The DX3 is a fantastic wall climber. It will scale the sides of your pool and scrub the vertical surfaces beautifully. But once it hits the top, it just turns around and goes back down.
The DX4 is a different animal. Thanks to those PowerStream jets, it reaches the top, sticks to the tile like a suction cup, and then moves horizontally. It spent about 20% of its cycle just scrubbing the “scum line” where the water meets the air. After using the DX4 for two weeks, I realized I hadn’t used my manual brush on the tiles once. If you hate that yellow/brown ring that develops at the waterline, the DX4 is worth every extra penny.
- WALL-SCRUBBING POWER: Dolphin Proteus DX4 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin's active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle on surfaces,...
Maintenance: Single vs. Multi-Layer Filtration
Both robots feature the top-load filter basket, which is the best design on the market. You just pop the latch, pull the basket out, and hose it off.
In my testing, the DX3 basket was great for leaves and large debris. However, the DX4 often comes with (or has the capacity for) finer filter inserts. Because the DX4 has dual brushes, it kicks up more fine silt from the floor, and I found its filtration system kept the water looking slightly “crisper” than the DX3. Both are incredibly easy to clean, but the DX4’s ability to handle larger pools (up to 50ft) means its basket is slightly better at managing a high volume of debris.
Dolphin Proteus DX3 Robotic Pool Vacuum Cleaner
- WALL-SCRUBBING POWER: Dolphin Proteus DX3 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin Proteus DX3 - active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle...
Pros:
- Affordability: One of the best values for in-ground pools under 33 feet.
- Lightweight: Very easy to pull out of the water (even for kids or seniors).
- Compact Storage: Takes up very little space on its caddy.
- Effective Scrubbing: The front active brush is much better than suction-only cleaners.
Cons:
- No Swivel: The cord will eventually tangle and require manual untwisting.
- No Waterline Cleaning: It leaves the most visible part of the pool (the tiles) for you to clean.
- Range Limited: Not suitable for large residential or commercial-sized pools.
Dolphin Proteus DX4 Robotic Pool Vacuum Cleaner
- WALL-SCRUBBING POWER: Dolphin Proteus DX4 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin's active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle on surfaces,...
Pros:
- Waterline Mastery: Truly scrubs the tile line, saving you manual labor.
- Tangle-Free: The swivel cord is a massive quality-of-life improvement.
- Extended Reach: 60-foot cord handles even the largest backyard pools.
- Dual Scrubbers: Two brushes are better than one for stubborn debris.
Cons:
- Heavier: A bit more of a workout to lift out of the deep end.
- Higher Price: It is a premium investment compared to the DX3.
The Final Recommendation: Which One Wins?
After living with both, my conclusion is based on the “Lazy Factor”—and I mean that in the best way possible.
I recommend the Dolphin Proteus DX3 if you have a smaller pool (under 30 feet) and you don’t mind a little “pool-side cardio.” If you’re okay with untangling a cord every few days and spending ten minutes a week scrubbing your own waterline with a brush, the DX3 will save you a few hundred dollars and still keep your pool floor spotless.
I recommend the Dolphin Proteus DX4 if you want to truly retire from pool maintenance. The combination of the anti-tangle swivel and the waterline scrubbing makes this a 100% autonomous experience. For anyone with a 40-foot or 50-foot pool, the DX3 isn’t even an option—you need the extra cord and the dual brushes of the DX4.
In my own pool, the Proteus DX4 is the winner. The first time you watch it move sideways along your tile line, scrubbing away the gunk while you sit in a lounge chair, you’ll realize that the extra cost was actually an investment in your own free time.
- WALL-SCRUBBING POWER: Dolphin Proteus DX3 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin Proteus DX3 - active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle...
- WALL-SCRUBBING POWER: Dolphin Proteus DX4 climbs walls efficiently, ensuring thorough cleaning on any pool surface, no matter the shape or surface type.
- ACTIVE SCRUBBING: Elevate your pool maintenance with the Dolphin's active scrubbing brush eliminates manual effort, guaranteeing a pristine pool. Gentle on surfaces,...
Frequently Asked Questions (FAQs)
Q: Does the DX4 have Wi-Fi?
A: No. While some “DX” series cousins (like the DX5i) have Wi-Fi, the Proteus DX4 focuses on mechanical performance and waterline scrubbing. It uses a weekly timer on the power box rather than an app.
Q: Can I use the DX3 in a vinyl liner pool?
A: Absolutely! Both the DX3 and DX4 are safe for all pool surfaces, including vinyl, fiberglass, gunite, and tile. The brushes are designed to be “gentle but firm.”
Q: Is the caddy hard to assemble?
A: Not at all. It took me about 12 minutes to snap the Universal Caddy together. It’s mostly heavy-duty plastic and doesn’t require any advanced tools.
Q: How long does a cleaning cycle take?
A: Both models run a standard 2-hour cycle. They scan the pool using an algorithm to ensure they don’t miss any spots, though the DX4’s route is more complex because it includes that horizontal waterline path.
Q: Why is my DX3 getting stuck on the main drain?
A: This can happen if your drain covers are very high. Sometimes, adjusting the “float” on the handle or ensuring the filter basket is completely clean can help the robot maintain enough “lift” to clear the drain.
