hydrometer

Can I measure my salinity by just putting the hydrometer in the tank itself or do I have to fill something up with my tank water and put it in that?

I've been calibrating my refractometer with RODI for the past 2 years. I now know that it's best to calibrate with calibration solution. I want to switch to calibrating with the solution with my next water change, but the problem that I ran into is when I calibrate using the solution my tanks...

I already own a delicate, glass hydrometer from Dupla. Plan on buying a digital refractometer, the Hanna one specifically. Should I own a handheld refractometer to double check the digital refractometer? The Vee Gee STX-3 is a bit of an investment, but I can't doublecheck with the hydrometer...

Good afternoon, Using tropic Marin pro reef mix (German); I have ~25 gallons and added 12 1/2 cups of salt and ended up with 1.010 on my refractometer after 36 hours (heater at 77 and power head in the brute container too) which idk why feels odd. The furniture I was planning to put the tank on...

I want to get into the habit of checking my salinity more often. The issue is using a salinity measuring tool that I can trust, and rely on without having to tinker with it every time. An analog refractometer requires quite a bit of tinkering and cleaning for one measurement. The Hanna Salinity...

Hello Where can I buy tropic marin hydrometer?