How do you test salt level?

Tamberav · Dec 12, 2019

I dip my finger in the water and lick it...repeat a few times just to be sure.

kidding... I have a VeeGee which isn't garbage and holds calibration.

JumboShrimp · Dec 12, 2019

There is, of course, the age old “consistent” vs. “accurate” dichotomy. If I throw 3 darts and they all group close together, but in the WALL and not near the bullseye, I throw ‘consistently’ but not ‘accurately.’ So my belief is that the Icecap is probably consistent enough for even some corals— but may not be accurate when compared to a finely calibrated refractometer. As I said initially, for a FOWLER it more than fits the bill / does the trick

MrsBugmaster · Dec 12, 2019

Alex Sadowsky said:
I use a VeeGee Scientific stx-3 refractometer. It’s a heavy duty lab grade refractometer. Super accurate and I have not had to calibrate it yet.

I use to have one of these also and it was always spot on. I loved that thing! Never had to calibrate it in two years. A little more expensive but worth it. Then I dropped it on the basement (cement) floor and cracked the prism. Then got a Milwaukee and was never satisfied with it. For some reason I could not get it to work properly, the directions were confusing to me. Now I went all out and got a Misco hand held digital. This refractometer is awesome! But very expensive. So it depends on your budget I guess. I would go with a VeeGee or a Misco if you got the money.

YankeeTankee · Dec 12, 2019

I'd recommend both a BRS refractometer (without LED!), and the Milwaukee. People who are serious and diligent about water testing are just so much more successful from what I've seen. I try to use 2 methods/tests for each parameter. I know that sounds like more work/$ but if you know what's in your water, you'll have a killer tank!

Urban · Dec 13, 2019

A word of caution with the calibration fluid, and this is something I found out the hard way unfortunately. I used two bottles of the same brand, and each time I would get ready to check my salinity I would grab one at random just to be on the safe side. I noticed that occasionally quite an adjustment would need to be made. This happened to coincide with a several month’s period of time that I had issues that I could not explain which seemed to come in waves.

After months of practically ripping my hair out at being unable to pinpoint the issue, it occurred to me that I should test both bottles. While one read 35ppt, the other read 30ppt. The expiration dates on the bottles were one month apart. Prior to this incident I would not have had multiple bottles, but one came with the refractometer, and not realizing this I ordered another. Theoretically, they should be spot on, and if you happen to notice that they aren’t, you will probably be told there was an error on your part (lid was left off, not stored properly, the refractometer wasn’t cleaned properly, etc.). I will go to my grave saying that this was not the case. The response that I was given aside from it most likely being a certain error on my part was that it is usually a good idea to have three or four different brands just to be safe if there happened to be a bad batch. As old school as it may be, I don’t think you can go wrong with a certified glass hydrometer, and afternoon that incident I bought one and won’t look back. There have been quite a few threads and articles on the subject that may be worth the read:

Glass Hydrometer (Am I Old School)

Glass Hydrometers, am I old school or just old? My first tank in 1980 I used a glass hydrometer, so that’s what I am comfortable with. Starting out in the ninety’s I read about refractometers that where not calibrated correctly and people having issues so I did not change. Then I tried the swing...

www.reef2reef.com

Chemistry And The Aquarium: Aluminum In The Reef Aquarium

In this article I will give some details of aluminum in natural seawater, and will discuss the sparse literature on the toxicity of aluminum ions to marine organisms.

www.advancedaquarist.com

bgoldb · Dec 14, 2019

I have used everything from the old school hydrometer to the certified research field Misco units and found the analog refractometers (red sea and another model) to be incredibly inconsistent. In addition, the calibration process is flawed. I was skeptical so I purchased and tested 3 different calibration fluids and they all delivered different readings. How can one rely on the readings of their refractometer if the underlying calibration solution isn’t even consistent or accurate? For something this important, I took the plunge and spent the money on the equipment that marine biology scientists use, Misco (Amazon product). I also have a Milwaukee unit, apex salinity probe and an Icecap salinity pen. I occasionally compare readings of all units and they are all very close.