HI98319 Hanna Marine Salinity Tester Review

One of the integral parts of keeping a reef tank is accurately measuring the salinity of your water.  Salinity is a measurement of the dissolved salt content within your water or simply a measure of how salty the water is.  Since marine fish, invertebrates, and coral come from the ocean we must mimic and optimize the water parameters in our home reef tanks for the long-term health and sustainability of our reef tank collections.  One of the things most tested in the hobby is salinity and it can be a bit of a cumbersome process to get an accurate reading.  

When I first started out reefing I used an Instant Ocean Hydrometer.  These work by filling the hydrometer up with your saltwater and reading the measurement on the hydrometer where the floating arm points at.  I found these classic type hydrometers to be a bit of a pain to use and at times could be wildly inaccurate.  Sometimes air bubbles would form on the indicator arm and it would make the arm float higher than it should.  Other times I would need to thoroughly soak and clean the hydrometer before using it so the arm wouldn’t stick.  The measurements are also a bit hard to read.

After about a year of battling the hydrometer, I moved on to the good old trusty refractometer.  Refractometers are great as I got much more accuracy with them and I used them for most of my reefing career.  The part that I didn’t enjoy so much is the process to use and get accurate results from refractometers.  First, you have to calibrate your refractometer both initially and ongoing to keep it accurate.  When you go to use it, you need to keep the dropper clean and the refractometer clean.  You use a pipette to apply a drop or two to the refractometer, close the window, and look through the eyepiece with light to get a reading.  After each use, a thorough clean is required to get an accurate reading the next time.  I found myself loathing this process when trying to get multiple readings in a short period.      

Enter the HI98319 Salinity and Temperature tester.  This tester by Hanna Instruments has truly been a process game changer for me and my reef-keeping maintenance.  My process went from the refractor process outlined above to simply dipping this device into the water source I want to measure and then wiping it off making it instantly ready for the next test.  Not to mention, that this tester also reads temperature which is helpful when getting your water ready for a water change.  

HI98319 Hanna Salinity and Temperature Tester Features

• On-screen digital display that displays temperature and salinity at once.  
• Displays salinity results in parts per thousand (ppt), practical salinity units (PSU), and specific gravity (S.G.)  
• Displays temperature results in celsius or Fahrenheit.
• The tester itself is waterproof and floats.  Both of these features have saved my bacon when I’ve dropped it in the tank.
• Uses CR2032 Li-ion battery for up to 100 hours of continuous use.  Includes an auto-shutoff feature to further preserve battery life. 
• Graphite sensors instead of stainless-steel help reduce polarization effects and do not oxidize over time for accurate reliable readings.  
• Automatically compensates salinity reading based on temperature.
• 1-year warranty.

What comes with the HI98319 Hanna Salinity and Temperature Tester

• The HI98319 Hanna Salinity and Temperature tester comes with everything you need to get an accurate reading right out of the box.  
• Protective hardshell case:  This is nice to have, but I haven’t used it since I purchased the tester and just store it with the cap on.  This would come in handy if traveling through.  
• Protective cap: Easily slides over the tip of the tester to protect the sensors.  
• 4x 35.00 ppt calibration solution sachets
• CR2032 battery
• Instrument quality certificate and instruction manual

How does the HI98319 Hanna Salinity and Temperature Tester Work?

The tester is simple to use.  Here are the steps for using the tester:

• Dip the tester in the tank or sample of water you want to test about 1.5” into the water. 
• Swirl the tester to dislodge any air bubbles.
• Wait a few seconds for the stability tag to disappear.  
• The result will be displayed on the screen.
• After use, rinse the probe with purified water and dry off.
• Replace the protective cap after each use

Does the HI98319 Hanna Salinity and Temperature Tester Need to be Calibrated?

The Hanna salinity and temperature tester requires an initial calibration and is recommended to be recalibrated monthly with normal use and more frequently with higher use.  The calibration process is simple by putting the tester into calibration mode and using Hanna’s calibration sachets to get a calibrated 35 ppt reading.  It is not recommended to use anything other than Hanna’s calibration solution which can be one drawback of the tester, but they are rather affordable.  

ReefSumpers final thoughts on the HI98319 Hanna Salinity and Temperature Tester

I love products that make the maintenance process side of reef keeping easier, and the Hanna salinity checker makes life easier.  It’s a joy to use when all you have to do is turn it on and dip it into the water and within seconds gives you a nice accurate reading including temperature.  I’ve had this tester for about a year, and it’s performed flawlessly.  The first few months I made sure to double-check salinity with my refractometer and have had no issues with accuracy and retired my good old refractometer.  I think that my testing and salinity levels are more accurate and consistent since the tester only tells you what the measurement is and removes the need to eye the measurement and determine the level of salinity.  So far, the battery has held up well.  I’ve had zero issues with the tester.  I test multiple tanks and do weekly water changes which so the tester has been put through reps and has performed brilliantly.  Overall, I’m happy with the investment and would highly recommend this product.