Ive been looking for a small shoaling fish and pencilfish look like a nice alternative to tetras/rasboras. I was just wondering what peoples thoughts are on them, and if they would mix well with my current fish (white cloud minnows, black widow tetras, pearl gourami). What is considered the minimum number to keep, and does there need to be any sort of male/female ratio? By tank is a Juwel Rio 125 btw.