I'm new to the hobby so please bear with me if this is a dumb question ...
I have a 150g tank that is set in the wall in my living room. The space it is in is basically the area under the stairs that go upstairs, and there is a door to gain access to everything. So basically it's a tiny enclosed room. This required the use of a chiller, which generates even more heat.
Because it's a small enclosed room and it gets hot, we get quite a bit of evaporation. This is replenished automatically with clean fresh water that also has some calcium in it.
So generally speaking, if you replenish what evaporates with fresh water, overall your salinity/SG
should stay about the same right? However, I do notice quite a bit of salt residue on just about everything in the room so obviously some of the salt is also leaving the tank via evaporation.
I don't know if this is the reason, or if my salinity has always been this low and I didn't realize it because I was using a crappy hydrometer, but I just bought a high-end refractometer and my water is about 1.022 which is too low according to the "expert" who helped set everything up. He says I want to be right around 1.025.
He is out of town for a few weeks and I am just curious how to go about raising it from 1.022 to 1.025. I assume there is some type of salt mix or other solution I can buy and slowly add to the tank to bring it up?