tank crashes are caused by negligence. they don't just happen.
let's face facts- the bacteria is on surfaces, it's not in the water column, so taking a few gallons of water from someone elses tank doesn't delete the cycle.
another fact is that bacteria needs fuel to survive. what fuel is present in this bottle of powder? a 5 year shelf life?
so, if in fact this bacteria in a bottle is actually on the surface of the powder inside the bottle, it would be absorbing nutrients all along until it's out of food, and then dies.
fact 3- no one cares what your grandma has to say.