The porous zeolite is host to water molecules and ions of potassium and calcium, as well as a variety of other positively charged ions, but only those of appropriate molecular size to fit into the pores are admitted creating the "sieving" property.
Zeolites have high CEC's, arising during the formation of the zeolite from the substitution of an aluminum ion for a silicon ion in a portion of the silicate framework (tetrahedral units that make up the zeolite crystal).
Zeolites dominated by exchangeable K for example, may be well-suited for plant growth applications while those dominated by Na should be approached much more carefully as Na in high concentrations can be detrimental to plants.
Zeolite is widely being used by livestock farmers as a feed additive for beef cattle, dairy cows, swine, poultry (boilers and egg production), and sheep.
Zeolite is a rumen buffer for the total digestive tract of high performance dairy cattle.
Zeolite is soluble in water and acid, so it is not flushed from the rumen as quickly as sodium bicarbonate.