Many barb species will nibble plants, but very few do it sufficiently to do any real damage. Certainly Ruby Barbs are not famous plant eaters. What is interesting is...
>>> plants which are green with red edges to the leaves
... makes me wonder about a couple of related things, are these plants truly aquatic plants, and if they are, do you have enough light. Red plants demand high light levels, if they don't get it, they will die and rot. If the plants are non aquatic, they will die and rot. In either case, they will become soft, and the barbs will munch away on them.
What kind of plants are these?