Testing rocks with vinager
yesterday I had my hardness tested due to an unusual ph reading and it turns out it was 900 whatever, so I did water change and will do more over the next few days. I removed the rocks and will test them with vinegar today 2 thinks what happens if they are unsuitable? and is it fool proof I mean if they don't fizz could they still be a problem?
The only other things in the tank other than flora and fauna is substrate (Dupla ground) which I believe is inert and the mopani driftwood that was soaked and boiled in our town water which is very hard. Could the driftwood be leaching that hard water?