Thats a vague generalization at best. There are many terrestrial moss species, more terrestrial than aquatic. This thread is over a year old, and to this day there are still many people that contend this moss specie in question is not an aquatic, and there are threads much older than this one with people complaining it simply dies in the aquarium. There are simular discussions, comments on plantedtank.net, aquaria central, aquahobby.com and aquariumadvice.com The general consensus doesn't seem to support you.Well, Ive had this plant in my tank for quite some time and its growing and doing fine. You will find that most mosses will live and grow underwater as they have evolved to living submerged at least seasonally in their natural habitat. If you provide enough light & additional co2 in your tank, this helps.