If you have a 55 gallon barrel of saturated kalk or a 5 gallon bucket of the same saturation the addition of 1 cup of liquid from either container will have the same impact on your tank parameters. When you get a bigger tank you will need to add more liquid from either container, everything else being equal the 5 gallon bucket will have to be refilled 11 times for each time you have to fill the drum.
The above presumed that both containers were filled with enough kalkwasser powder so that the maximum saturation was attained in both, which is my understanding of how these things work. I use a calcium reactor myself, so if I am wrong about “saturation” someone will point out my error of the concept.