My red eyes nose rubs went away without any treatment. Likely, the tank is too small or something is just not right in their environment that caused it. Doesn't hurt to have some SSD cream on hand for treating it though, just to prevent infection. Otherwise you could try plain neosporin (no painkiller) though the ssd cream is a better option.

EDIT- Did he mention any other issues? The mouth doesn't look quite right on the one.