We have tested both the Clear S and the Dolphin Sigma in real pools, measured their suction at the intake, and lived with the filtration and daily routine each one requires. This comparison brings those results together so you can see the real-world trade-offs without relying on the numbers printed on either box.
Both use corded power, so this matchup turns on measured pull, filtration, coverage, automation, and value.
The short answer: Dolphin Sigma is our pick. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin. Clear S still has a clear case: it is the better fit for buyers who want Clear's cleaning performance at the lower price.
Quick Answer
Buy the Dolphin Sigma when its strengths match your pool. Best for: buyers who want near-Premier power with full app control. It is the stronger choice across the measurements and ownership factors that matter in our testing.
Choose the Clear S instead when its narrower advantages matter more to you. Best for: buyers who want Clear's cleaning performance at the lower price. It matches the Clear UV at 2.09 PSI and keeps the same filtration and coverage for less.
Our calls in the full reviews are Recommended for the Clear S and Recommended for the Dolphin Sigma. Those calls matter here: PSI is the first round, not the entire verdict.
Suction Power: 2.09 PSI vs 2 PSI
On our hydro manometer, the Clear S measured 2.09 PSI and the Dolphin Sigma measured 2 PSI. That gives the Clear S a 0.09 PSI advantage, or about 4% more intake pressure than the lower reading.
We measure pressure directly at the intake with the same gauge and pool setup. That is different from manufacturer flow-rate claims in gallons per hour: GPH describes water movement, while PSI shows how hard the intake pulls on debris. Cordless results are recorded at full charge. Our complete pool-robot suction test explains the method and shows where both robots sit on the full board.
The number needs context. It matches the Clear UV at 2.09 PSI and keeps the same filtration and coverage for less. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin. The stronger gauge result gets this round, though intake pressure alone cannot make up for a filter that lets fine debris escape or a routine that makes you handle the robot every day.
Filtration and Debris Handling
The Clear S uses high-surface-area ultrafilter rated around one micron. The Dolphin Sigma uses top-loading pleated nanofilter cartridges for fine dust, pollen, and silt.
Filtration is effectively even in our scoring. The better choice depends on the debris in your pool and which basket or cartridge design you prefer to rinse.
For leaves, capacity and intake design matter. For pollen, silt, and the haze that dulls otherwise clear water, the filter media matters more. A basic mesh screen can look clean after a run while still passing the smallest material back into the pool.
Automation and Daily Work
The Clear S is corded. App and power-supply controls with scheduled corded cleaning. The Dolphin Sigma is corded. MyDolphin Plus app works underwater and supports weekly scheduling.
Because both are corded, neither needs a recharge. The meaningful question is how much scheduling and remote control each power supply or app provides.
We score automation as a tie.
Coverage and Pool Fit
For the Clear S, our review found floor, walls, and waterline with the same cleaning platform as the clear uv. The Dolphin Sigma is built for floor, walls, and waterline with the widest intake path we have measured.
Coverage is a tie in our scoring, so choose around pool size, shape, and the surfaces you actually need cleaned.
This is where the runner-up can still be the smarter fit for specific pools. A compact pool does not benefit from paying for reach it cannot use, while a pool with a sun shelf, long waterline, or heavy leaf load can expose the limits of a simpler machine quickly.
Value: Performance for the Money and Time
Our value take on the Clear S: The value-focused Clear: the same measured pull as the UV model without paying for the lamp. For the Dolphin Sigma: Expensive, but it combines elite suction, filtration, navigation, and app control.
The value edge goes to the Clear S.
Value is not the same thing as the lowest checkout price. We count cleaning power, filtration, how many surfaces the robot covers, and how often you have to retrieve or charge it. A cheaper robot that leaves you vacuuming behind it is not a bargain, and an expensive robot only earns its price when its extra capability solves a real problem in your pool.
Which One Should You Buy?
- Buy the Dolphin Sigma when its strengths fit your pool. Best for: buyers who want near-Premier power with full app control. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin.
- Choose the Clear S instead when its specific trade-off fits better. Best for: buyers who want Clear's cleaning performance at the lower price. It matches the Clear UV at 2.09 PSI and keeps the same filtration and coverage for less.
- Know the main drawback: Dolphin Sigma — Its premium price is hard to justify if a power-supply timer is all the control you need. Clear S — It does not include the UV-C feature that distinguishes the Clear UV.
Final Verdict
Dolphin Sigma wins this comparison. Dolphin Sigma wins the overall matchup. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin. Clear S remains the better fit for buyers who want Clear's cleaning performance at the lower price.
Read the complete Clear S review and Dolphin Sigma review for every test photo, setup detail, and long-form ownership note. You can also return to all pool-robot comparisons to see any other matchup from the 19 cleaners in our test set.
