refractometer calibration

[ducati1212]

So I think my salt is off. I have a 3 month old red sea refractometer and 35 ppt calibration solution. I put the solution in tonight after not doing it in a month and my refractometer was reading high 40 ppt.

I adjusted it with the screw down to 35 and retested and it was fine.

I did the same thing 1/2 hour later and it was 40 ppt again. was just double checkig my work so I adjusted and got it to 35 ppt. waited 5 min tried again it was pretty close still.

now im curious so an hour later I get my solution and test again and its 40 ppt again. Now im not sure what my tank is

Can refractometers do this or am I just that rusty after an 8 year break. cant see what im doing wrong.

thoughts?

 

[FishAndPhysics]

Make sure the axles of the coverslip are moving freely, its important that the layer of saltwater is flat, not wedge shaped. This usually shows up in mine as a blurring of the line.

If I'm actually mixing saltwater right rather than just checking the salinity of my tank, I always calibrate first.

 

[ryeguyy84]

Seems like somethings wrong with it. I stopped using my refractometer and bought one of these.

https://clearchoiceaquatics.com/collections/testing-supplies/products/marine-salinity-tester-hi98319

Love it so far, for the first week or 2 I checked it with my refractometer then stopped double checking.

Sent from my SM-G950U using Tapatalk

 

[ducati1212]

Seems like somethings wrong with it. I stopped using my refractometer and bought one of these.

https://clearchoiceaquatics.com/collections/testing-supplies/products/marine-salinity-tester-hi98319

Love it so far, for the first week or 2 I checked it with my refractometer then stopped double checking.

Sent from my SM-G950U using Tapatalk

I just bought that an hour ago it comes in Tuesday. Until then I feel my salinity is at risk. I don't get what I'm doing wrong I mean it's a water drop

 

[homer1475]

The Red Sea refractometer is known for not being able to hold it's calibration. Never read of it being this bad, but I have read about them drifting in a couple days of non use.



I have and use the milwaukee electric salinity tester. Just bought the hanna as it looks to be easier to use, and Hanna has a very good reputation in the hobby for reliable test kits.

 

[ryeguyy84]

You're going to love it, dip, read, rinse. Calibration is just as easy and they recommend monthly

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