One thing, if you like to water every day/or every other day (I do too), then coconut husk chips will probably stay way too wet for you, the hardwood charcoal would work by itself, and mounting is also a great idea, since your other catts like that. The ones that like to be a little wetter, maybe you could just pot those instead. Just use the largest, chunkiest media you can find, like an inch or so (around 25mm or so). Good Luck! Ooh, and post pics of your mounted ones too.