salinity increasing

So i am almost to the point that i am ready to start adding coral to my tank, ive gotten all my stuff setup and my tanke has been aging for a while, i will still wait for the 6 month mark but i have a question about salinity. I am currently using red sea salt (not the coral pro) but im wondering...

Good afternoon reefers, I have a quick question, so i have a Reefer 425xl and i am using the ATO reservoir that came with the tank using the float switch for ATO. The last few weeks when i been doing water changes, i have noticed the salinity in the display is always 0.02 higher each week so i...