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The trusted solution for monitoring critical water resources
Water quality and aquatic habitats around the world are revealing how development and climate change are impacting our streams, rivers, lakes, and coastal waters. Providing data that's critical to ensuring environmental compliance and implementing mitigation programs, HOBO data loggers are trusted worldwide for monitoring our most valuable water resources.
See Our Top, Time-Saving Water Quality Monitoring Products
We're committed to providing cutting-edge, streamlined water quality monitoring solutions that deliver research-grade data for the parameters you need.
Data Logger
HOBO MX Underwater PAR Data Logger
Delivers highest-accuracy measurements of photosynthetically active radiation (PAR), temperature, and tilt for both underwater and above water environments.
Solution Kit
HOBO MX801 DO & Temperature Data Logger
Fully submersible, Bluetooth-enabled MX801 logger and Dissolved Oxygen (DO) / Temperature sensor for water monitoring applications. .
Solution Kit
HOBO MX801 Conductivity & Temperature (CT) Data Logger
Fully submersible, Bluetooth-enabled MX801 logger with accompanying Conductivity and Temperature sensor for water monitoring applications. Accessories can be added below.
Solution Kit
HOBO MX801 Conductivity, Temperature & Depth Data Logger
Fully submersible logger with Conductivity, Temperature, Depth (CTD) sensor. Options available for 13, 30, 100 or 250 feet. Freshwater or saltwater.
WATER QUALITY WEBINAR
Collecting & Quality-Controlling Dissolved Oxygen Data: A Buzzards Bay Study
Wireless Data Loggers for Water Quality Monitoring
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MX2502
$1199.00 USD
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MX80x
$520.00 USD
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MX2501
$875.00 USD
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MX2202
$99.00 USD
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MX2203
$165.00 USD
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|---|---|---|---|---|---|
Bluetooth |
Yes | Yes | Yes | Yes | Yes |
Temperature |
Yes | Yes | Yes | Yes | Yes |
Conductivity/Salinity |
N/A | Yes | N/A | N/A | N/A |
Depth |
N/A | Yes | N/A | N/A | N/A |
Dissolved Oxygen |
N/A | Yes | N/A | N/A | N/A |
pH |
N/A | N/A | Yes | N/A | N/A |
Light |
Yes | N/A | N/A | Yes | N/A |
Tilt |
Yes | - | - | - | - |
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View product | View product | View product | View product | View product |
Streamlined solutions for reliable, long-term water quality monitoring
We have a deep history providing innovative solutions for monitoring temperature, dissolved oxygen (DO), conductivity, salinity, pH, light, and more. Measure multiple water quality parameters at once, seamlessly download data via Bluetooth in the field, and store and share data using LI-COR Cloud®—our award-winning wireless MX loggers simplify your deployment and data collection!
Water Quality Applications
Frequently Asked Questions (FAQ)
FAQs
HOBO water quality loggers measure:
- Dissolved Oxygen (DO) — critical for aquatic life health
- Conductivity and Salinity — indicates pollution, saltwater intrusion, or mineral content
- Water Temperature — affects all other water quality parameters
- Depth / Water Level — for understanding water column dynamics
- pH — measures acidity/alkalinity
- Underwater PAR (light attenuation) — affects aquatic plant growth and ecosystem health
Dissolved oxygen (DO) is the amount of oxygen gas dissolved in water — it is the primary driver of aquatic life survival. Fish, invertebrates, and aerobic bacteria all require sufficient DO. Low DO events (hypoxia, below ~2 mg/L) cause fish kills and ecosystem collapse. DO levels are affected by temperature, salinity, turbulence, algae growth, and organic decomposition. Continuous DO monitoring with HOBO loggers allows researchers and regulators to detect hypoxic events, track seasonal patterns, and assess the health of streams, estuaries, and coastal waters.
Key HOBO water quality products include:
- MX800 Series — Bluetooth multiparameter loggers for DO, conductivity, salinity, temperature, and depth with interchangeable sensors
- MX2501 pH/Temperature Logger — Bluetooth pH and temperature monitoring
- U26-001 Dissolved Oxygen Logger — stand-alone DO logger for long-term deployments
- MX2502 Underwater PAR Logger — PAR, temperature, and tilt for aquatic light studies
- MX2202 Pendant Temp/Light Logger — affordable light and temperature monitoring
HOBO MX series water quality loggers (MX800, MX2501, MX2502) use Bluetooth Low Energy to communicate wirelessly with the free HOBOconnect app on smartphones, tablets, or Windows devices within approximately 100 feet (30 m). The MX802 direct-read model allows data download without removing the sensor from the water — significantly reducing disturbance at monitoring sites and saving field time. Data can then be synced to LI-COR Cloud with an MX Data Plan.
HOBO water quality loggers are designed for freshwater, saltwater, and estuarine environments including: streams and rivers, lakes and reservoirs, coastal and tidal waters, coral reefs, wetlands and estuaries, groundwater and monitoring wells, and aquaculture/hatchery tanks. Titanium housing options are available for long-term saltwater deployments where corrosion resistance is critical.
DO sensor calibration frequency depends on deployment conditions and required data quality. For research-grade data, calibration before each deployment is recommended. The HOBO MX800 series features guided calibration within the HOBOconnect app that automates the process — typically taking only minutes. The DO sensor cap on the MX800 is user-replaceable, extending sensor lifespan. Regular calibration checks (every 2–4 weeks for long deployments) are advisable in environments with high biofouling potential.
Related Resources
Seamless Light Monitoring with the New HOBO Underwater PAR Data Logger
Learn how this multiparameter logger with Bluetooth data offload streamlines aquatic monitoring of photosynthetically active radiation and underwater light attenuation with industry-leading accuracy.
Monitoring Wetlands with Data Loggers: A Best Practices Guide
Learn field-proven best practices for configuring, launching, and deploying portable data loggers in wetland monitoring applications.
Thought Leader Webinar: Hypoxia in a Subtropical Estuary, Development of a Regional Monitoring Network
A free, on-demand webinar with guest presenter Dr. Austin Fox on the development of a regional monitoring network to inform estuary restoration efforts.
Lobster Thermal Preference Study
Researchers studying the thermal preferences of female lobsters are using HOBO data loggers to tag lobsters and monitor water temperatures in the Bay of Fundy/Gulf of Maine.