Im working on a django app, where i can create silos and their capacities e$.$g Wheat$-50$t$..$ The silos contain a unique grain$\_$type say wheat. A given grain type can exist in $1$ or more silos $($e$.$g $3$ silos of $50$t containing wheat$).$ during brewing, i draw grain from the silos for example if i want to use $10$t of wheat, i just update brewing logs by selecting the grain type and what has been used. When i need to draw from a given silo and there isnt enough quantity, draw what is left and the rest from another silo with the same grain type.

notify if qty is below $50\%$