I set up my new dirted 125 with Saf T Sorb a little over two weeks ago. Everything is fine so far and the fish are all doing well. But, as expected the pH is much lower than what comes out of the tap. I have done a couple small water changes, so don't cause a huge pH swing. I am also waiting to add new fish until the pH stabalizes and gets back up to normal (or at least close to normal). For those of you who have experience with STS, how long does that process take? Also, will I be OK doing 25% weekly water changes?