how do you test pH?
you can just add universal indicator if it is a liquid and see teh olour it turns
if it is red to yello it is acidid, if it is green it is neutral and if it is blue to purlple it is alkaline
The most commonly used one (in schools anyway) is Coulor matching used Benedict's test and a coulor chart to match the correct pH value
you can buy pH testing equipment at stores. usually used for pool water. too much Cl can be bad. not enough can also be bad.
Liftus paper? or something like that.