depends on the species i guess. also looking at your sig i see you have clown loach AND 2 common plecs in a 110l? i assume youre asking thos because you know your tank is way too small for even 1 common plec and want to know how long you have to upgrade to a 6 footer for these 16 to 20 inch plecs? if not those are gonna need re-homing
nope, bigger plecs such as commons and gibby's can, with good conditions, grow up to 1" every month, they do slow down once they get to 12".
any less than 1/2" growth each month and i'd say that the plecs growth is being stunted