Sutro vs. EcO from iopool Review - Which is the better one?

Sutro vs. EcO from iopool Review - Which is the better one?

There are many pool/spa/hot tub water monitors available, and it can be hard to compare them. Don’t worry; we are here to help and help you get the best one for your case.


The Sutro checks water chemistry levels like ph and chlorine (or bromine) three times daily, alkalinity once daily, and temperature every hour.

The Sutro monitor is a floating device that can be placed directly inside your pool, spa, or hot tub. 

When the Sutro detects that your water is not balanced, it will notify you and suggest how much and what types of chemicals you should add to re-balance your water again. 

For this, the Sutro measures:

  • Temperature
  • Free Chlorine
  • Acidity (pH)
  • Alkalinity
  • Bromine

When you get a result from Sutro, it will tell you exactly what to add to rebalance your water and how much chemicals it needs. 

You could simply scan the barcode on the chemical brand you have on hand, and Sutro will automatically calculate how much you need to add. 

The Sutro app, which can be paired with the Sutro Monitor, is available in the Apple and Google Play Store.


Works well with

The water monitor works the following types of Pools, Hot Tubs, and Spas:

  • Chlorine
  • Saltwater
  • Mineral
  • UV
  • Bromine


The price for the Sutro device starts at $499, and it requires a monthly subscription of $29 for the primary or $39 for the premium subscription. 

The subscription covers:

  • BASIC ($29/Month)
    On-demand cartridges shipped to your doorstep; Expert recommendations based on the chemicals you own; E-mail and chat support.

  • PREMIUM ($39/Month)
    Everything in BASIC + Front of the line VIP Support with a certified CPO, Weekly Water Health report, Monthly Pool Pro Consultation, Detailed Historical Graph


  • Monitors water chemistry 3x times a day 
  • Uses LaMotte and Taylor reagents, the gold standard of the pool industry
  • Tells you which chemicals to add, how much and when to add them 
  • All chemical brands compatible
  • It works with hot tubs and spas
  • Can be used outdoors


  • Reagent cartridge needs to be replaced once per month 
  • Needs subscription

Get the Sutro pool monitoring system here.

EcO from iopool 

The EcO Start Pool Monitor from IoPool measures the pH levels, disinfection capacity (ORP), and water temperature every 15 minutes. It also comes with a pack of chemicals from ioPool. 

It is a self-balancing floating device that runs on a battery and can be placed directly inside your hot tub, pool, or spa. 

It connects via Bluetooth with the mobile app, but your smartphone has to be within 10 meters of range to establish a connection. EcO also offers a Connect+ module (sold separately) which allows you to connect this monitor via wi-fi and access it from anywhere in the world. 

The app shows you personalized suggestions for rebalancing the water according to the current water chemistry. It tells you about the quantity of different chemicals to add. However, the values are only for the ioPool-branded chemicals which come with the package. 

You can use your preferred chemical brand, but you’ll have to adjust the quantity accordingly (based on concentration). 

The EcO pool monitor measures the sanitization potential of water using the Optimal Redox Potential (ORP), measured in milliVolts (mV). It is calculated based on these factors:

  • pH or potential Hydrogen;
  • TAC or Complete Alkalimetric Title;
  • The stabilizer rate;
  • The free chlorine level.

Works well with 

The EcO pool monitor works with the following types of hot tubs, spas, and pools:

  • Chlorine
  • Mineral
  • Bromine
  • Oxygen


The basic EcO Start pool monitor costs $250 and comes with the following items:

  • The EcO analyzer
  • Ph down, 1 kg
  • Ph up, 1 kg
  • Fast chlorine-1kg orActive Oxygen-1kg orBromine-1 kg
  • Start Guide
  • One dosing spoon
  • Five test-strips
  • Free iopool app access

There’s also an advanced bundle called the EcO Start and Connect, which allows you to connect this monitor to the wi-fi. It costs $304 and includes a wi-fi/Bluetooth gateway on top of the regular package contents. 


  • Lightweight, discreet, and easy-to-use
  • Excellent life of battery and sensors (at least two seasons)
  • Personalized recommendation on which chemicals to add for rebalancing chemistry
  • No monthly subscription costs
  • Works with hot tubs, spas, and pools
  • It comes with test strips and pool chemicals


  • It does not work with saltwater pools
  • Sends recommendations relevant to IoPool brand chemicals
  • It doesn’t work below water temperatures of 15°C (50°F)
  • Maximum range of 10 meters only
  • Understanding ORP may feel ‘too technical’ for some pool owners


While the EcO Start is a cheaper and easier option, with a longer lifespan, and better warranty, it needs to catch up to Sutro in accuracy and technology. The Sutro Pool Monitor uses the gold standard of water measurement and is incredibly accurate. Additionally, the value of ORP sounds more technical compared to the simple free chlorine/bromine readings. 

The Sutro Pool Monitor can also work with saltwater pools, unlike the EcO start. The app for Sutro is more intuitive and versatile, whereas the app for EcO is modeled around their line of pool chemicals. Additionally, Sutro works with pool chemicals of all brands but the EcO is limited to its own line of chemical products. 

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