Dependent on the size of the aquarium that is true. However with a 30 or smaller bns, or otos are the choice. But anything over 55 a royal will clean up well. Also Farlowellas do a good job, but they get long.
For BNs I had one that took out so many cats, 1 4" BN took out an 8" chocolate pleco, 6" common, 4" striped raphael cat, 4" chocolate cat, 5" Banjo cat, 3" talking cat. There were a few others, but I can't remember them off the top of my head. He was a great big bn too, with great colors, but meaner than heck. Locally I see ancistrus of the much larger varieties. There is a shop in spokane that had 2 that were both 10", and one locally that has a 10" bn. The unfortunate part about BN is that it is generic like "Common" plecos. There are several species that stay around 4", but at small sizes they can look identical to the species that get to 10".
For BNs I had one that took out so many cats, 1 4" BN took out an 8" chocolate pleco, 6" common, 4" striped raphael cat, 4" chocolate cat, 5" Banjo cat, 3" talking cat. There were a few others, but I can't remember them off the top of my head. He was a great big bn too, with great colors, but meaner than heck. Locally I see ancistrus of the much larger varieties. There is a shop in spokane that had 2 that were both 10", and one locally that has a 10" bn. The unfortunate part about BN is that it is generic like "Common" plecos. There are several species that stay around 4", but at small sizes they can look identical to the species that get to 10".
