Hanna Salinity Tester Review: Is It A Smarter Way to Measure Reef Tank Salinity?
Quick Answer: The Hanna salinity tester measured within 1.2 PPT/PSU of two separate reference solutions.
The real question is what that means for you. Was the testing approach solid enough to trust the result? Is ±1.2 PPT accurate enough for your reef tank? And maybe most important, will it hold that accuracy over time or require frequent recalibration?
For most reefers, that level of accuracy is likely good enough to maintain a stable environment, especially when consistency matters more than chasing a perfect number. But long term reliability and drift are where the real test begins.
Use code FREE at checkout to unlock a full week of SR access.
Below is a 60 second preview of: TESTED! Will The Marine Salinity Tester Measure Up? | SR LABS
Quick Links:
Hanna Salinity Tester: Check out the details
Randy Holmes-Farley DIY Conductivity Solution: A DIY Calibration solution.
Full Hanna Salinity Tester Video: Use code FREE at checkout to unlock a full week of access
*These links are provided as a quick way to find the items discussed in this video. Serious Reefs earns a small commission when they’re used. Using them is a convenient, free way to support what we do here. Thank you for your support.
TESTED: Is the Hanna Salinity Tester Accurate Enough for Reef Tanks? | SR Labs
The hanna salinity tester is one of the most popular digital tools in reefing but can you actually trust it?
Salinity is a “small number, big consequence” parameter. Even minor errors can impact coral health, alkalinity demand, and overall tank stability. In this SR Labs test, we put the hanna salinity tester head-to-head against a lab grade conductivity meter and a standardized reference solution to find out how accurate and reliable it really is.
What we tested:
• Accuracy vs a lab-grade WTW 3620 conductivity meter
• Performance against Randy Holmes-Farley’s 35 PPT reference solution
• Temperature compensation from cold RO water to tank temps
What we found:
The hanna salinity tester consistently measured about ~1 PSU lower than a lab-grade reference. That sounds like a miss—but it’s actually very close to the expected accuracy range for hobby-grade meters.
More importantly, it was repeatable. The tester produced the same offset across multiple tests and standardized solutions, which means it’s predictable—and that’s what really matters in reefing.
Temperature performance was also solid. As water warmed from ~15°C to ~25°C, readings only shifted by about 0.1 PSU, tracking closely with lab-grade equipment. That’s a big win for a handheld device.
So is the hanna salinity tester good enough?
For most reef tanks, very likely.
A consistent ~1 PSU offset is unlikely to cause real-world problems, especially if you understand your tool and use it consistently. In fact, repeatability is often more valuable than chasing perfect lab accuracy.
The bigger question is long-term usability. Will it stay “dip, read, rinse,” or require constant calibration? That’s what we’re continuing to test and will update
Bottom line:
• The hanna salinity tester is consistent and predictable
• Temperature compensation performs better than expected
• It reads slightly low (~1 PSU), but within a usable range
• Long-term reliability and calibration needs are the next test
In reefing, no tool is perfect. What matters is whether it’s reliable enough to make good decisions—and consistent enough to trust trends over time. Right now, the hanna salinity tester looks promising on both fronts.
Coming next: We compare this against refractometers and other salinity tools to see what actually performs best in real reef tanks.
