Trust Hanna or refractometer?

[toadstool_paradise]

So I’ve been using some no name brand refractometer for a year and a half on my tank but was never sure if it was accurate. I’ve been having some real issues with my corals and wondered if something was off. My refractometer reads 1.025-1.026.
Got a Hanna salinity tester and when I put it in the calibration solution it read 35 PPT exactly. Does this mean it will 100% read my salinity accurately? Because if this is true, it read my salinity as 31.9 PPT which is pretty low. I don’t know what to trust, would like some help. Always calibrated my refractometer with distilled water. It always read the same in my tank.

 

[xxkenny90xx]

I would lean towards the Hanna but get a third test done to confirm. Either get a floating hydrometer or just have your lfs do a test

 

[toadstool_paradise]

I would lean towards the Hanna but get a third test done to confirm. Either get a floating hydrometer or just have your lfs do a test

I may head up to the LFS tomorrow so I will do that and hope for the best! Thank you.

 

[xxkenny90xx]

I may head up to the LFS tomorrow so I will do that and hope for the best! Thank you.

No problem! Bring both of your testers with you and test their water.

 

[toadstool_paradise]

No problem! Bring both of your testers with you and test their water.

Ohh good idea will do.

 

[Greg P]

... Always calibrated my refractometer with distilled water ...

This may be the issue with your refractometer, and your tank could very well be @ the 31.9 you measured. This translates to 1.024 Sg and isn't terribly low, but it is borderline for many corals. I've read 1.023 is the lower limit so you're pushing it.

Many brands require using calibration solution to 35ppt.
Using straight water is asking your unit to calibrate to zero which will vary widely at our needed levels. The more you move away from the calibration point the more the unit will vary.
If you want to keep using your refractometer as a backup or to check against the Hanna, get some calibration solution from a trusted brand.

 

[toadstool_paradise]

This may be the issue with your refractometer, and your tank could very well be @ the 31.9 you measured. This translates to 1.024 Sg and isn't terribly low, but it is borderline for many corals. I've read 1.023 is the lower limit so you're pushing it.

Many brands require using calibration solution to 35ppt.
Using straight water is asking your unit to calibrate to zero which will vary widely at our needed levels. The more you move away from the calibration point the more the unit will vary.
If you want to keep using your refractometer as a backup or to check against the Hanna, get some calibration solution from a trusted brand.

Yep the Hanna was right. Have slowly upped my salinity to 1.025
And also got some calibration solution for refractometer too! Thanks!