since MammothP isn't cheap, i recently took my last 20ml or so & "extended" it by mixing with molasses/filtered water, let them do their thing for a week in warm/dark, then into the fridge for safe keeping. then use at 1-2 tbsp/gal when i feed in bloom. un-refrig'd, they take off and will consume the whole thing.
it's not science, for sure, but the resulting funk smells the same as the original and it sure isn't hurting them because the weed is right.
i plan on repeating it the cycle when this gallon gets run down & maybe increase the size of the innoculant/amount of "starter" bugs. it would be cool to have a lab check the bacteria types & #s then...i'm at almost 2 years on my original small 70$ bottle now.
i have a feeling that the 4 MammothP bacteria are super f'n hardy after reading up on them; at least one was actively cultured on an >aluminum< substrate. so i used some aluminum foil as my "gasket".
can't say i enjoy it, but i enjoy smelling the results!