I have a 6.75 " male, I have committed a lot a mistakes during raising him that have been fixed by me along the way helped with a lot of advising of experimented people from here and also from personal friends aswell, the mistakes include no proper WC, no proper foods, sickness several times caused by tubifex feeding where I got him,no a big tank for eight fish(55g),etc. I have that male since he was 3 months old, he is currently 2.25 years. If all of those mistake had not happening, how big would be that male as of today?. Yes,I think that some individuals could reach the eight inches or close. I have heard of more than that.
Guillermo