Some is "ok". Some people prefer the roots to be pristine, so there's no chance of getting any perlite or vermiculite into the tank (the little white balls). They can possibly present an impaction hazard.

Most mosses are shipped in a dormant state (dry) this avoids insect issues. Best bet for cleaning it is to rinse thoroughly under cold water, then a very mild (5%) bleach dip, then rinse again in Dechlorinated water.


Education is the most powerful weapon we can use to change the world ~ Nelson Mandela