These guys are around 4-5cm big. 
I just have fine grit. 
This tank has only been up for a week but i transferred all the water from their old tank into the new one including their filter. 
I just have gouramis and BN and corys 
 
I feed them on frozen blood worms, freeze blood worms, frozen brine shrimp, thera +A, freeze dried tubifex and discus tucker and they do eat my corys shrimp pellets. 
 
In probably about a month  they will be moving into a bigger tank