Water Monitor

For hydroponics, laboratories, water-quality monitoring, aquariums, brewing

The Water Monitor is unavailable until further notice.

Water Monitor (front)
Water Monitor (front)
Water Monitor with sensors (front)
Water Monitor showing pH, ORP, conductivity, and temperature

Measures water temperature, pH, Oxidation-Reduction Potential (ORP), and conductivity/TDS. Battery-powered with long life, or plug in.

pH probe

ORP probe

Conductivity probe




(3-Wire PT-100 RTD temperature sensor included)

Buy for $175

Water Monitor only ships to the USA for now. Expect that to change soon!

We're confident this is the best value in water monitoring you'll find. Accurate enough for laboratory use. Affordable enough for anyone.

Send readings to your PC or Raspberry Pi using the built-in USB port. View on your phone or computer using the open-source readings viewer, or Python library:

Water monitor screen

Water monitor built-in display

app screenshot

Screenshot from the viewer software

Download the viewer

Monitors pH, electrical conductivity, Total Dissolved Solids (TDS), temperature, and Oxydation Reduction Potential (ORP). Available with all, some, or none of these probes. pH, conductivity, and ORP probes use BNC connections, and temperature probes use 3-wire screw terminals.

The temperature sensor is a Pt100 Platinum Resistance Temperature Detector (RTD). TDS measurements are temperature compensated.

Built to last

The Water Monitor is designed to be run for extended periods of time, with little to no maintenance. Its long battery life makes it suitable for use in environments with no nearby electrical outlets.

Easy calibration

Calibration screens use interactive intstructions. Use 2 or 3 point pH calibration, and single-point ORP and conductivity calibration.

Water Monitor pH calibration

Suitable for continuous immersion

Features a 4.2" e-paper display that's clear and readable, even in bright sunlight.

Long battery life, or power with USB-C

Has a 3-week+ battery life using 3 AA batteries (included), or power it with a USB C port, using the included cable and plug. Compatible with rechargeable batteries. Use as a portable meter, or in places without a nearby outlet.

Use as a portable sensor suite, or leave submerged indefinitely.

Built-in hook for wall-mounting. Can be used with 1, or 2 mounting points.

User manual

Updating firmware

Connect to a Raspberry Pi using MyCodo for detailed logging, remote monitoring, and charts.

Hub specifications:

Temperature sensor specifications:

pH electrode specifications:

ORP electrode specifications:

Conductivity electrode specifications:


Here are some alternatives to consider, which also provide multi-sensor water monitoring: