Hmm.... I dunno! I just water with RO water is all. I try to water every 3 days or more often unless I'm out of town (then it's 5.) The moss goes dry in between waterings. Not completely dry; not enough to kill it because it always perks up after I water.

Recently one of my pots got TOO dry and the moss died and is white and needs replacing. To me, moss is like a lawn and I'm a stickler for ugly moss. I hate it!

Oh yeah, the plant is claimed. Trade over.