Marica, I use zeolite as part of my soilless mix. I use 1:1:1 mix, pumice/#2 cherrystone/zeolite. The mix holds moisture, extremely fast draining, very airy, and in my case I find it almost impossible to over water.

Joe

Yes the happy cat and other products too that are pure zeolite. It's an exceptional container substrate.

Interesting. I will look this up!