I run tanks for breeding and tanks for grow-out. Mixing those jobs makes selection harder and wastes space.
My ratio
Personally I select about 5–6 males for 50 females. That ratio is how I stock breeding tanks when I’m serious about a line.
Selection
Males are chosen carefully — pattern and quality matter. Females carry the numbers. This pairs with how I grade: keepers push the line; project stock and culls teach the next move.
Farm note: Observation first. Hours watching behavior taught me more than any shortcut. Ratios only work if the animals are healthy and the water is boringly stable.