Are yo-yo loaches usually aggressive? The reason I'm asking is because I have been thinking about getting some, but I think I will have to get another tank set up as my current tank is already getting near maxed out. Right now I have a 29g set up and I have 2 black skirt tetras, a bala shark, pleco, 2 adult mollies, 2 baby mollies and fixing to have some more babies this week. I'm also fixing to add 2 angel fish to the tank. Im not keeping the fry as for my shark will eat them and I don't have the room for them.