If you place certain bacteria in water that has a pH below 6, they enter a form of stasis. I know that at least some of the BB we use reacts the same way, so my guess is that they are using that type of method.
If you place certain bacteria in water that has a pH below 6, they enter a form of stasis. I know that at least some of the BB we use reacts the same way, so my guess is that they are using that type of method.