In order for us to help we need more information. Possibly the amount of grams you used for Mg in trial 1 or something similar to this.
Answer:
outgassing of elements from earth's interior
if it is edible you can taste it if it taste bitter its a base and if it taste sour then it is a acid if it taste like nothing like water would it would be a neutral substance.you could also order a ph tester which is just a liquid that you drop in it.
yw:)
