My first bet is on the Chinese algae loach, just due to them not really being a decent algae eater and more of an omivore eating any soft plant matter they can find, least that's what I notice IMO. My second bet is actually on the rummynose tetra's. They are known to tear plants up actually. I have some in my 40 and they are constantly digging in my glosso, I don't notice any damage but I have seen a few accounts of it from others.