I got him when he was about 5-6cm.
hes pretty smart,one day i opened the lid to feed him and he came up to the top of the tank and flicked his tail at me and covered me with water and it was dripping off my face.
yesterday when my dad went near his tank grouch opened his mouth as far as he could and showed his teeth to try and scare him,so dad got some frozen prawns out of the freezer and defrosted them and gave them to him then he was happy.
thanks for the ideas everyone i will probably just get some more fake plants for him to move or rearange the other ones this weekend when i clean the tank so he isnt bored.
By the way grouch is my oscar.