I am doing a fish less cycle of a 45 gallon tank. I am curious why the pH would be rising. I have driftwood, playsand (which I thought would be inert), and plants. The water from the tap (that sat in a bucket overnight with Prime) is around 7.6, but the last couple of tests I have done with the tank water was at 8.2. I thought it might be caused by ammonia, but it's only at 0.5...?