Help! Salinity Reading Issues

i find that sometime my hydrometer is a bit high as well. It may have to do with very small bubbles clinging to the swing arm. I always give my hydrometer 3 or 5 good whacks with my finger, hold it by it's top portion only so it's free swinging, and look on it at eye level.

I would personally always trust a refractometer though. As long as you calibrated it correctly (you did, didn't you?) it should be your definitive SG. Using a hydrometer over a correctly calibrated refractometer would be like trusting a magnifying glass over a microscope.

 

Okay, here's a broad answer to all the responses:

I did calibrate the refractometer with RO/DI water - twice. The instructions said to calibrate with DI water. Gave me the same readings on the tanks after both calibrations.

I re-tested the tank that gave my hyrdometer the high reading 5 times, and every time it was 1.028.

I don't have vinegar but will get some today. I'm soaking the hydrometer in water and will re-test the tanks to see if there is any change.

 

I know. But the refractometer instructions said to use DI water....

 

The Calibration solution is just distilled water.

 

Okay, well I'll look into getting some of that. I guess I better lower the salinity in my 37 then and not trust the refractometer until I get some of that solution.

 

is RO/DI water the same as just distilled water?

 

no, reverse osmosis and distilling are two different processes. distilled water is actually cleaner than RO water in some ways. however distilled water carries a higher pricetag to create. RO/DI systems are so much cheaper than a true distiller.

you can do a quick google search on Reverse Osmosis versus Distilled water and yield some good articles on it.

 

Yes and no. Distilled water goes through a process called distillation (who would have thought it would be named that) where the water is boiled and the vapors hit a cool sheet of glass and reliquify. The water then runs through a coil into a container. Suppose to be pure H2O, but everyone has their own opinions.

 

They are practically the same thing.

 

Okay. Well...I dunno what to do!! Lol I calibrated the refractometer several times and it gives me the same readings both times.

I let the hydrometer sit in a water solution for a bit and ran water through it, and it gave me the same readings. I'll get some vinegar today to clean it better.

I guess I'll lower the salinity in my 37 a bit, but not do anything to my 90. I don't want to raise it if it's really high enough and the refractometer is wrong.