Moving some goldfish today 🧡 Breeding goldfish in cold water is all about working with their natural seasonal instincts instead of fighting them. Step 1: Start with healthy adult goldfish. Choose fish that are at least one year old, well-fed, and active. Females will look rounder in the belly while males may develop small white breeding spots on their gill plates and fins. Step 2: Condition them with better food. Feed high-protein foods like pellets, gel food, bloodworms, or brine shrimp for a