tropic marin high precision hydrometer

I bought my hydrometer before Tropic Marin started including the vase with it. I emailed Brian of Tropic Marin USA on Sunday during the holiday weekend asking if i could buy the vase. He reponded within 2 hours and said they aren't available individually for sale yet but he would send me...

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...

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...