One of my 40 gallon planted tanks is having some issues with one of the fish nibbling my Val and sagettaria only. I have one angel a flame gourami a zebra loach a yoyo loach and 6 cherry barbs. None of these fish are known for eating plants which is why I have a concern. The leaves are being chewed off and not finished and I can't seem to catch anyone doing it. All the fish have been nibbling at the unfortunate java moss one of my buddies asked me to revive but as far as interaction with plants that's it. Help!