The short answer
Goldfish are omnivores and thrive on a varied diet. Build it around a quality sinking pellet made for goldfish, add plenty of vegetables, and keep protein moderate — especially for round-bodied fancies, where too much rich food and floating flakes lead to swim-bladder trouble. Feed small amounts once or twice a day, only what they clear in a minute or two. Little and varied beats a lot of one thing.
A balanced menu
- Staple: a good sinking pellet designed for goldfish. Sinking food means less gulped air than floating flakes, which matters for fancies.
- Vegetables: blanched, de-shelled peas, courgette, spinach or cucumber add fibre and aid digestion.
- Occasional protein: small amounts of bloodworm or brine shrimp as a treat, not a staple — too much protein is hard on fancy goldfish.
Don’t overfeed
Goldfish will beg constantly and never look full, so the biggest risk is overfeeding. Uneaten food rots and spikes ammonia — hard on a fish that already makes a lot of waste — and overfed fancies are prone to constipation and buoyancy problems. A useful rule: if food is still drifting after a couple of minutes, you gave too much. A weekly fasting day helps digestion too.
Feeding and water quality
Because goldfish are messy, feeding and filtration go hand in hand. Feed lightly, keep strong filtration, and change water regularly. Browse the fish food hub for suitable pellets, and read how often to feed fish and do goldfish need a filter? to round out the routine.