How can you fill in Visa papers it’s dark, don’t be surprised when they won’t let you in! Lol
On the salinity probe, the only way I can get it to read correctly. Is get something you trust, like my old Red Sea refractometer now replaced by the Hanna salinity checker, and when your happy it’s at 35 or whatever you want, when it says dip in the solution, put it back in the tank, that is the solution. Then it will work and match what you trust.
They need cleaning around every 3 months so be warned, because when you’ve just landed and are having a beer in your hotel room relaxing, you will get an alarm saying the salinity is at 50!