What are your thoughts on handheld hydrometers? Are they a reliable and accurate tool for measuring salinity?

[myrcies]

Hello everyone!
I had a bit of an error recently and accidentally did not realize my salinity had been rising for some time (reaching about ~1.035).
I think the issue was that I purchased saltwater from a local shop and stored it in an open-air bin. I have since moved everything to a proper small water barrel to help mitigate this issue.

However, I also think my testing may not be proficient. I struggled a bit to properly measure salinity and had some issues getting proper readings.
As such, I am hoping to get a better tool to measure it more accurately and more often.

What are your thoughts on handheld hydrometers? I have been considering the Fluval or Instant Ocean models but am concerned if they are deemed safe for aquariums.

 

[exnisstech]

Cheap atc refractometer and some of Randy's diy calibration fluid is my go to salinity tester. I've been using this one for over 8 years.

 

[drewzaun]

I was always told hydrometers are useless but people who are doing this longer than me, have nicer reefs than mine and are brave enough to make YouTube videos about their tanks use them, so I guess anything used properly is good.

However trust nothing, calibrate everything.

 

[Tahoe61]

I don't trust them, over time mine just tended to become more and more inaccurate.
I use a Milwaukee that I calibrate with each use and test against a sample of SW at 35 ppt.