Gear
Refractometers and salinity meters: what reef keepers commonly use
Refractometers and conductivity pens for checking salinity. Below are 2 items we see often, each with our honest note and where to view it in the UK and the US.
We sell nothing and earn nothing from these links. Prices are as each retailer's page showed them on the date checked, and they change. How this guide works
Listings checked . How we check
What should you look for in salinity meters?
- Automatic temperature compensation.
- Calibration with a 35 ppt seawater standard. Pure water alone only checks zero.
- A second method to cross-check now and then, since a drifting meter can walk the whole tank off target.
Commonly used salinity meters
Specs are as published on the listed pages. Where the US and UK pages give different figures, we show both.
Milwaukee MA887 digital refractometer
Brand: Milwaukee Instruments
Our note. A digital refractometer for seawater that removes the guesswork of reading a scale. Accuracy is plus or minus 2 ppt, so check it against a 35 ppt standard.
Key specs
- 0 to 50 PSU; 0 to 150 ppt; 1.000 to 1.114 SG
- Accuracy +/- 2 PSU or ppt, +/- 0.002 SG
- Automatic temperature compensation
UK listing
Kraken Corals (UK): opens the retailer's page for Milwaukee MA887 digital refractometer in the United Kingdom- Price as shown
- £129.99
- Checked
US listing
Bulk Reef Supply (US): opens the retailer's page for Milwaukee MA887 digital refractometer in the United States- Price as shown
- US$159.88
- Checked
Hanna HI98319 salinity tester
Brand: Hanna Instruments
Our note. A waterproof conductivity pen that reads salinity in seconds and comes with calibration sachets. It is not a refractometer and needs regular calibration at 35 ppt.
Key specs
- 0.0 to 70.0 ppt / PSU; 1.000 to 1.041 SG
- Accuracy +/- 1 ppt up to 40
- Single-point calibration at 35 ppt
UK listing
Kraken Corals (UK): opens the retailer's page for Hanna HI98319 salinity tester in the United Kingdom- Price as shown
- £78.95
- Checked
US listing
Bulk Reef Supply (US): opens the retailer's page for Hanna HI98319 salinity tester in the United States- Price as shown
- US$99.99
- Checked