Find out your ph first....if it's off it doesn't matter what you do to it....fix the ph.

Not to be mean...but i've heard several people say the same thing as you did and I'm curious....why would you not test the ph before assuming it was low and why not test the ph of what you are adding....especially since you have access to some sort of ph tester.

Again...I apologize if I sound mean or rude; it's just that I've seen several people do that kind of thing and am curious as to why you'd approach it like that.