Do you mean Porous Stone?
I would say the Porous Stone since it evenly distributes the nutrients to the plants.

I would put one for each plant on a airpump. (directly underneath)
If you would want the same results as from the other plants I would recomment taking a measuring cup divide the nutes between the plants of your choice.
Then put this much in the measuring cup and pour it underneath the plants roots.
I would mix some Superthrive into it also.