Yeah, I don't mind testing the water, I enjoy bragging when people ask who my pool service is :-) l am just worried they might say "Look here, back in 1998 your pH was over 7.8, so therefore we are not fixing the leak under your spa" or something like that. That's probably exaggerating it a little.. plus for some reason I don't think this builder will be around much longer given my experience.

I think you're right though with accurate records, even if it is me and not a "professional" doing the testing. Showing years of logs would go a long way in front of a judge.