I feed my plecos watermelon and honeydew and the corys loves to munch on those as well. I have also seen them on mu squash (summer and winter) which I also feed to my plecos. Cucumbers are pretty low in nutrients, so I don't usually feed them to my fish.Just watch him with the corys though, sometimes the rainbow sharks will shoulder the corys away but it's normal. Also, this is totally out of context, but would corys like cucumber? Are there any other foods that they like?