Chris French and Helen Johnson wrote in
:

Litmus wouldn't be much good, but if you have kids at secondary school
they could probably cadge a bit of Universal indicator paper.

B-)

Ok...I only got a 'C' in chemisty (And it was a bloody long time ago!) so I
got the wrong type of paper!

You can buy a very simple kit at your gc.
You can also get pH meters as well.

Is it worth getting one?
Will they last if kept in safe in my toolbox?