[Peter Beyer]

As to pH measurements:
The only Problem with Lawrence is that he tends to forget things. At this Occasion, he did not bring his pH meter (while I did bring the conductivity meter – just to make this clear). So I uged him to make use of his sensory experience in water chemistry, which he then did, as can be seen in the two attached photos. This way he came up with a pH of 4.375. I have no reason for doubt!