Does anyone ever get Xenia just growing in your tank when you didnt put it in there? None was added to my tank, just one day I noticed it (well I think thats what it is, but could be something else), its growing, currently about 1/4 of an inch high. The thing I am not sure about though is that it doesnt seem to grow off a bigger stalk, instead, each little individial stalk is just on the rocks.