3-4cm rosy barb. Water Quality: Will require a water temperature of 18° - 23 °C with a water pH of 6.5 - 7.0. Compatability: Peaceful - This fish is fairly peaceful although some may be a bit more dominant than others. They will nip the occasional fin and should be kept in groups to keep fin nipping to a minimum. Diet: As a Omnivorus species a mixed diet including meat based and vegitable matter for optimal nutrition. You can get food with such ingredients such as flake, small pellet, wafer mix and frozen or live The rosy barb (Pethia conchonius) is a subtropical freshwater Cyprinid fish found in southern Asia from Afghanistan to Bangladesh.