Cymbifolium Thuidium ( Thuidium cymbifolium )Thuidium cymbifolium is a very easy plant to keep without much extra care, but like all plants, it can benefit from CO2 supplementation, although this is not required. Like many mosses, it does not typically respond positively to most chemical plant supplements. Many aquarists report success with this moss purely through keeping a well maintained aquarium with no supplementation. When planting in terrariums plant in an area that is not overly moist.