I tested my DIY rock from the rock making party which was only about 4 weeks ago and lo and behold the ph was down to 8.4. A few days ago it was still off the charts. Of course my little arch is much smaller than some of the larger pieces but then again those are in a stream and mine was in a bucket which I did change a few times a week. So maybe you might check one out John and see how they are perculating. Anyone else check their rock lately?