HouseholdRobot.netAquabot X4 vs Dolphin Sigma: Full Comparison
Last updated: May 19, 2026 | Side-by-side spec comparison
Quick Summary
A budget-vs-premium pairing of corded inground pool cleaners. The Aquabot X4 ($799, 15 m cable) is the entry point for credible robotic pool cleaning — floor + walls, no waterline. The Dolphin Sigma ($1,799, 18 m cable) is Maytronics' flagship: dual active scrubber drive, longer cable, waterline scrubbing, and a deeper service network. For routine maintenance on smaller pools, Aquabot is more than enough; for larger pools, heavy debris, or pools with biofilm/scale issues, the Sigma earns its premium.
Spec Comparison Table
| Specification | Aquabot X4 $799 | Dolphin Sigma $1,799 |
|---|---|---|
| Price (USD) | $799 | $1,799 |
| Cable length | 15 m | 18 m |
| Wall climbing | Yes | Yes |
| Waterline scrubbing | No | Yes |
| Drive | Wheels + brush | Dual active scrubber |
| Cycle time | 1.5–2.5 hr | 2–3 hr |
| App / remote | Basic remote | WiFi app + remote |
| Cartridge filter | Yes | Yes (NanoFilters) |
| Service network | Limited | Wide (Maytronics) |
| Warranty | 2 years | 3 years |
Cable Reach
Aquabot's 15 m cable is enough for pools up to roughly 8–9 m on a side — the cable has to span the entire pool plus reach a power source above grade. The Sigma's 18 m cable handles pools up to 10–11 m. Beyond that, look at the Polaris 9650iQ Sport with 21 m or a cordless option like the Beatbot AquaSense X.
Drive System: Sigma's Big Advantage
The Sigma uses two active counter-rotating scrubbers as its primary drive. They scrub the floor and walls continuously while moving the robot — biofilm and light scale come off in the same pass. Aquabot uses a more conventional wheels-plus-brush layout: the brush agitates but the wheels are passive. On a clean pool the difference is small; on a pool with recurring algae or hard-water scale, Sigma's active drive is noticeably more effective.
Waterline Scrubbing
The Sigma climbs to the waterline and scrubs the band where oils and sunscreen accumulate. The Aquabot X4 climbs walls but does not scrub the waterline. If you have a heavily-used pool with sunscreen and body oil residue forming a visible ring, this is a meaningful difference.
App and Control
Sigma supports Maytronics' WiFi app for remote start, status, and cycle selection. Aquabot ships with a simple wired/IR remote — you have to be poolside to operate it. For households where the pool equipment is in a separate enclosure, the WiFi app is worth real money.
Parts and Service
Maytronics (Dolphin's parent) has the largest US service network for pool robots, with authorized repair centers in most metros and easy access to spares (tracks, impellers, cables). Aquabot's service network is smaller and parts can take longer to source.
Verdict
Pick the Aquabot X4 if
- Pool is up to roughly 8 m on a side
- Routine debris cleaning is the goal — you don't have algae or scale issues
- You don't need waterline scrubbing
- $1,000 saved matters — entry into robotic pool cleaning
Pick the Dolphin Sigma if
- Pool is up to about 10–11 m and you want a single robot to handle it
- You have recurring algae or scale issues that need active scrubbing
- You want waterline cleaning included
- WiFi app remote control matters
- Maytronics service network availability is important