hebe,
i got 2 8" with a 14"(well 14 when i measure last. hes put on substantial wieght and willing to bet hes longer)
very minor fin niping though he does follow them aroung. domenence has been established so its settling. he doesnt even try to eat them
My 18" florida completely ignores 4" convicts, but I'm sure others would gladly eat them. It depends on the gar, and since yours is already ignoring the small dats that's a good sign.