Smart pool monitors continuously track pH, chlorine, and salinity, sending alerts before imbalances become algae blooms. We compare Sutro, WaterGuru, Ondilo ICO, and Pentair — plus a whole-home leak detector pick for pool plumbing protection.
Whole-home smart water monitor that detects leaks and abnormal flow across your plumbing — including pool auto-fill lines — sending instant app alerts and optionally shutting off water automatically to prevent costly damage.
If you've ever opened your pool cover in spring to find a green swamp where your crystal-clear pool used to be, you already understand the case for smart pool monitors. Traditional test strips and drop kits give you a snapshot — a single moment in time — but water chemistry drifts constantly. A pH spike overnight, a chlorine drop after a pool party, a salinity shift after heavy rain: by the time you dip a strip, the damage may already be done.
Smart pool monitors float, plumb in-line, or clip onto your equipment pad, continuously measuring pH, chlorine (or ORP), alkalinity, salinity, and temperature. They push readings to a phone app and alert you when something drifts out of range, so you can adjust chemicals before a minor imbalance becomes an algae bloom or a scaling problem.12
This guide covers the leading dedicated pool monitors on the market — Sutro, WaterGuru, Ondilo ICO, and Pentair IntelliTouch — and explains what each does best. We also recommend a whole-home water monitor for leak protection on pool plumbing lines.
> A note on availability: The dedicated pool monitors below (Sutro, WaterGuru, Ondilo ICO, and Pentair IntelliTouch) are not currently available through our affiliate product database. We cover them here as editorial recommendations based on published reviews and manufacturer specifications. Our formal pick — Flo by Moen — is the one product we can link to directly. We may earn a commission on that purchase.
Sutro is the closest thing to a "set it and forget it" pool monitor for residential pools. The device floats freely in your pool or spa, measuring pH, free chlorine, and total alkalinity in near-real-time. Readings sync to the Sutro app, which sends push notifications when chemistry drifts outside your target ranges and recommends specific chemical adjustments.3
The trade-off is a subscription model: Sutro uses replaceable reagent cartridges that typically last about a month, and the monthly fee covers both the cartridge and cloud service. It's a floating design, so there's no plumbing to cut — you simply drop it in. That makes it the easiest install of any monitor in this guide, though some users report the floating unit can get caught in skimmers or around pool cleaners.12
Best for: Pool owners who want the simplest setup and don't mind a subscription.
WaterGuru Sense takes a different approach: it installs in-line on your existing plumbing (typically in the pump pad area), sampling water as it circulates rather than floating in the pool. It measures free chlorine and pH, then uses its app to provide dosing guidance — telling you exactly how much chlorine or acid to add.4
The in-line design means more accurate, consistent readings because water is actively flowing past the sensor. Installation requires cutting into your plumbing or using a bypass loop, which may call for a pool professional. WaterGuru is optimized for traditional chlorine pools and doesn't cover saltwater chemistry the way some competitors do.12
Best for: Chlorine pool owners who want precise dosing guidance and don't mind a more involved install.
Ondilo ICO is the standout pick for saltwater pool owners. It's solar-powered, so there are no batteries to swap, and it measures four parameters: pH, ORP (oxidation-reduction potential), salinity, and temperature — the full set most saltwater pools need.5
Connectivity is a strength: ICO supports both Wi-Fi and LoRa (a long-range, low-power protocol), so it works even when your pool equipment is far from your router. The companion app provides recommendations and tracks historical trends. One consideration is that ORP-based chlorine monitoring can be less intuitive than direct free-chlorine readings for users accustomed to traditional test kits.1
Best for: Saltwater pool owners, especially those with equipment located far from their home Wi-Fi.
The monitors above focus on water chemistry. Pentair IntelliTouch is a different category entirely: a full pool automation controller that manages pumps, heaters, lighting, water features, and — with compatible sensors — chemistry from a single interface.6
IntelliTouch (and its competitor, Hayward OmniLogic) is designed for new builds or major equipment upgrades. It requires professional installation and represents a significant investment, but it's the right choice if you're building a smart pool from the ground up and want everything — variable-speed pump schedules, heater timers, LED lighting scenes, and chemistry monitoring — under one app.1
Best for: New pool builds or full equipment-pad overhauls where integrated automation is the goal.
While the dedicated pool monitors above aren't yet available through our product links, there's one smart water device we can recommend directly — and it solves a problem every pool owner should think about: plumbing leaks.
Flo by Moen is a whole-home smart water monitor and automatic shut-off valve. Installed on your main water line, it continuously tracks flow rate, pressure, and temperature, learning your household's normal usage patterns. When it detects a leak — whether from a burst pipe, a running toilet, or a pool auto-fill valve stuck open — it sends an instant alert to your phone and can automatically shut off the water to prevent damage.12
For pool owners, the relevance is specific: pool auto-fill lines, booster pumps, and equipment-pad plumbing are common sources of slow leaks that waste water and can damage equipment over time. Flo monitors the entire home's water flow, so if a pool fill valve fails open at 2 AM, you'll know before your water bill does.
What we like:
What to consider:
Pool type matters. Saltwater pools need salinity monitoring, which narrows the field to devices like the Ondilo ICO. Traditional chlorine pools have more options, including Sutro and WaterGuru.1
Installation preference. Floating monitors (Sutro) are the easiest to deploy — just drop them in. In-line monitors (WaterGuru Sense) require plumbing work but offer more consistent readings. Full automation systems (Pentair IntelliTouch) need professional installation and are best planned during a build or renovation.2
Subscription costs. Sutro's cartridge subscription is an ongoing cost to factor in. WaterGuru and Ondilo typically have lower recurring costs but may require occasional sensor replacement. Compare the total cost of ownership, not just the sticker price.2
Connectivity. If your pool equipment is far from your Wi-Fi router, look for LoRa support (Ondilo ICO) or a device with a hub that bridges the gap. Bluetooth-only devices limit how far you can be from the pool to check readings.1
Smart home integration. If you're building a broader smart home ecosystem, consider how each monitor fits. Pentair and Hayward systems integrate with pool equipment natively. Flo by Moen works with Alexa and Google Assistant for voice alerts.6
Continuous water chemistry monitoring is one of the things actually worth buying if you own a pool — it saves time, prevents costly chemical imbalances, and catches problems before they become visible. Among dedicated monitors, Sutro is the easiest to deploy, WaterGuru Sense offers the best dosing guidance for chlorine pools, and Ondilo ICO is the clear choice for saltwater setups. For full equipment-pad automation, Pentair IntelliTouch is the professional-grade option.
For leak protection on your pool plumbing — and the rest of your home — Flo by Moen is the one device we can link you to today, and it's a smart addition to any pool owner's water-management toolkit.
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Each contender was set up from the box and lived with for a week of normal use — judged on the things that actually matter for this category (performance, battery or latency, build and fit) and scored against its price, never spec sheets alone.
