jidoka's clay mix didn't react at all the the fizz test. Maybe one bubble. BAS fizzed pretty well, and my native soil was like a mentos in a diet coke.
Spacey,
We have seen that in some soils that even if there is no reaction at all, there can still be major issues with carbonates. Some soils will not show a fizz unless you dig deep and even then carbonates can still make for a huge influence. Often we have to dig deep to actually get a fizz. The fizz test is not always that useful. With that said, it it does fizz, there are usually huge problems.