MaiReef
Valuable Member
I have used a refractometer for many years and a hydrometer as a second test. The hydrometer was always about 1.5 ppt low. No problems until I noticed the problem when I started dosing 2 part. I normally test salinity when I do water changes. The last two times my refractometer was out of focus and I figured I would just use the hydrometer and refocus and calibrate my refractometer when I have time to fiddle with it. So after 2 weeks my Calcium and Alkalinity were too high for my tank(520 and 12.2 Dkh). No big deal. I could just stop dosing, but my magnesium was a bit low and this puzzled me. So I ran all my tests and couldn’t get my refractometer(still working on it) to focus. It final led to me going to the LFS last night to have my water tested. Thanks Eddie’s. So basically what I found was that my magnesium was fine, but my Salinity was 1.029. OUCH! BTW everything looks fine in my tank, except for one damsel with a single eye popeye. I thought he scraped it so, I was just monitoring it for now. So today I opened a new hydrometer that I had in the box to see the difference between old and new. Well despite the new one being a bit high(normal to be off a bit). I found this. Hopefully, this can be a lesson to get people to buy and learn to use a refractometer and get a new one if necessary. Cheap tool, but very important. I am slowly bringing my salinity down and getting a new refractometer.
