Raising from what to what? Small enough numbers and I'd just consider it user/tester error. For example, if you have Alk of 8.1 and Calcium at 400 and the next time you test it's 8.3 and 430, I wouldn't worry about it. OTOH, if you went from 8.1 and 400 to 9.5 and 550, it would be worth looking into.
You could try doing 2 or 3 tests in a row (doing them the same way you always do, don't be any more careful (or sloppy) than usual) and see if you get consistent results.
More importantly, if you're doing regular water changes, test the alk and calcium on the new salt water. You might find that the calcium and alk are already higher than where your tank is and that's what's bringing it up.
I use Reef Crystals and, despite my DT running at about 8dkh, I found the Reef Crystals, when mixed to 1.025, have an alkalinity of 12ish. I do small, infrequent, water changes, which is probably why my alk ran down to 8, but those small infrequent water changes with 12dkh water is probably why I rarely have to dose anything (maybe some Soda Ash once a week or so).
So:
A)What are the actual numbers you're seeing?
B)What salt mix are you using?
C)Are you doing water changes and if so, how often and how much?
D)Are you dosing anything like two-part or adding any other chemicals to the tank?
E)How new is the tank and did you use dry rock that might be leaching something into the water?*
*No idea if dry rock could do something like this, but I know, both from reading and from my own tank, dry rock can cause odd things to happen over the first year or so. Hell, I still don't have detectable nitrates and my tank is pushing a year old.