I'd be a bit leery of Pictus with Os. They never really get out of snack-size territory.
If set on them,try the Colombian variety over the Peruvian.They have a larger adult size and are a bit more "tough".Told apart like this...Peruvian has larger body spots with smaller spots on head,Colombian has "peppering" of small spots over entire body with almost invisible spotting on head.
Last thing...if you use Pictus,have a secure hood.They like to range about at night feeling with those "whiskers" and sleeping fish have been known to jump being touched.