heh... they grow FAST ! Inches per year. I had one almost 2 years , he was about 5" when I got him and after trade in he was 16" nose to tail ! The tiger knives, my personal fav, are a bit slower growing then the clown but not much.
Whats a BGK? A black ghost? If so, they are very much more slower growing but hide a lot more and are more inactive then the others.
Man I havent heard these fish mentioned in 20 years or so ! Thanks for the memories!