[Brita]

I used to have a chemical from Germany that I used to measure pH and Temporary Hardness in water.  I filled a vial to 5 mm and added the yellow liquid one drop at a time.  If there was alkalinity or temporary hardness present, it would turn the sample bue or grey on the first drop.  I counted the number of drops it took to neutralize the sample and this told me how alkaline the water sample was.   I cannot find anything anywehre that fits this description and I cannot source this chemical from Germany.

[Alex]

it may be 'Bromcresol green' but i'm by no means certain. Have you got any more information about it?