how much did you buy? if you only bought a small amount then you might just want to not use it, but... if you do use it cannot help you on that. sorry! i used such a long time ago and used it once i really cant remember how i went about it. now... sorry
@Randy Holmes-Farley but it did raise my ph

so i will say it works. maybe not for everyone but it worked for me. also your tank is so small that it might raise it super quickly. so i would just test every day for a week to see how much a small amount would raise it like maybe a half teaspoon or something like that. just look it up to see and to lots of tests. moniter calc, alk mag, and stuff like that to see if it raised those a lot