Measuring Salinity / Specific Gravity in Aquariums

[KStatefan]

Not sure if I knew that or not but I was referring to the hydrometer salinity correction charts, when using a hydrometer, maybe the one I use is incorrect, I have checked it, don’t get the same results if I heat the water to the correct calibrated temp (I use a certified thermometer to 0.1c) here it is if you want to give it the once over?

Salinity Correction Calculator

Aquarium calculator; Correct a relative specific gravity (sg) measurement taken with a non-temperature-correcting unit.

www.hamzasreef.com

That calculator gives close to the same results as Randy's formula of 0.00019 per 1° F. I would guess the difference is just rounding error. Average difference for my last couple months was -0.000090 S.G.

 

[Lee adams]

Was it collected near shore or after a heavy rain? Most offshore NSW will read 1.024 to 1.026 specific gravity units. If you got your water from offshore, then I would suspect that your measuring device isn't accurate. One way to confirm that is to measure it with some other device to see if they agree.

Jay

We take the water from around 10 meters from shore which is already reef..As a wine producer hobbyist,I know how to use a hydrometer!
I was also surprised but it is what it is I guess.