We have tested the blue litmus with multiple pH buffers. The blue paper is blue at pH 8. At pH 7, the sample is maybe just a little red. The real change to red seems to start with pH 6.5 and lower.
We have tested the blue litmus with multiple pH buffers. The blue paper is blue at pH 8. At pH 7, the sample is maybe just a little red. The real change to red seems to start with pH 6.5 and lower.