a lot of bettas and gourami, shallow ditches and streams... not quite a puddle 😉What fish live in muddy puddles?
know the feeling for BBA on wood... would a UV make a difference?
When ive had this problem in shrimp tanks i have always left it be for 3 months or so then really go it persistently for a few weeks will direct liquid carbon and scrapping off during water change etc and it seems to go away in the fluffy form. Instead i end up with little black dots which never grow. Redmorr root is by far the worst for it. However tough to beat a curtain of Aponogetons 🙂