My tinfoil barbs used to hang around my OSCAR when he ate and pick up the scraps that spew out of his (her) gills.
They also ... (barf) like to pick up the oscar's craps... and eat em. I guess oscar's digestive systems are inefficient enough that the poo has some nutritional value and (gag) flavor leftover from the cichlid pellets.
They sometimes bite the oscar's buttock when it is comming. No joke. I am not sure a smaller kind of cyprinid such as filamentous barbs or spanner barbs would do the same, but they definitely would eat the tiny chunks that come out of the O's gills. Unless you have a 150 + gallon tank I would not suggest tinfoil barb.
Filament barbs grow to about 6 inches and Spanner/T barbs grow to 8. Rosy barbs are SUPPOSED to grow 6 inches but that is a world record or something, 4 inches is generally their max size.
You would probably have to add a bit of flakes for the barbs until their mouths get big enough to eat pellets whole. Depending on the pellet size this may never be unnecessary. I have no idea how long it takes for these sorts of barb to grow up, but if you get them at less than 2 inches they could become prey.
What size of tank do you have? If it is a 55 you are full up already.
