I had posted a thread about the same topic a few days ago, my salinity went from 1.027 to 1.030 since i started dosing more of the two part supplement(i used b ionic). It seems that after calcium and alkalinity are consumed, the end solution is salt, thus raising salinity. Sorry im not stating the exact compounds, i took chemistry a long time ago, but maybe someone can chime in in more technical words
I found out my salinity was high over the weekend, and am now working on getting the sg down with more diluted wc's...