Crytocoryne willisii is a lovely looking plant with pure green leaves. Originating from the Highlands of Sri Lanka, this crypt has evolved naturally from a different species of plants into what you see today. In a planted aquarium this plant will grow larger than it will in the wild, up to 20 cm, but the leaves will be much narrower and more pointed.
Understanding Crypt melt - all Cryptocoryne species require stable water parameter and light conditions. Once planted, Crypts should not be moved otherwise it can trigger what is called Crypt melt. If a Crypt has a significant change of environment (ph, kh, gh, lighting intensity or duration, root disturbance etc), Crypt melt can be triggered. The leaves start to disintegrate as the plant prepares for its new environment - DO NOT WORRY! Your plant will begin to grow back over the next 30 days (sometimes sooner, sometimes later) - it's still very much alive and busy getting ready for the growth of new leaves. In the meantime, any decaying leaves should be trimmed and recycled in a compost bin.