Well, I found the three stones and the pH paper. One of the stones was a 330mate one from Mark - a brilliant deal by the way, and a quality stone.

I tested the water first - pH neutral at 7.

I then rinsed a DMT with the water, raised a slurry on the stone, and applied the paper before rinsing the DMT again and repeating.

All the stones went towards the alkaline end - not by much, maybe half a step to one step on the pH scale.

I then honed a razor on each of the hones, and retested the slurry - same as before or so slight a difference as to being virtually undetectable by the paper.

To put that into perspective, sea water is about pH 8.

With the three sample stones I used I don't think that the stone itself could be responsible for any detrimental effect to the metal of the blade, giving the short time of immersion in the water on the surface of the stone.

So that leaves other factors to be considered - the most obvious ones being the actual pH value of the water used by the individual and the actual stone used. Next I would consider if the tape had any bearing on results - after that - who knows?

Regards,
Neil

PS: I hone over a trough - the trough catches water and I don't empty it that often, which means it has the slurry from shaptons, thuringians, CFs, BBWs, coticules, arkansas and other stones, mostly natural ones, in it. So I tested the water - it too was pH 8 or just a smidgeon above.