How much, how often and what to feed — building color and health without fouling your water.
By Chen Hao · 2026-08-24
Feeding and water quality are the same equation viewed from opposite ends. Every gram of food your fish miss becomes ammonia within hours; the filter converts it, the plants absorb some, and the rest accumulates until your next water change removes it. Feeding discipline is therefore water-quality management.
A fish's stomach is roughly the size of its eye — a useful mental image whenever the temptation to add 'just a little more' appears. Most adult fish thrive on one to two small meals a day with a weekly fasting day.
Start with a quality staple matched to mouth size: micro-pellets for small cyprinids, fine flake for surface feeders, sinking wafers or tablets for loaches and gobies. Pellets retain nutrition in water longer than flake and make portioning honest.
Then rotate in frozen foods two or three times a week: bloodworm, daphnia, brine shrimp, mysis. Native stream fish are insectivores at heart, and the chitin in whole invertebrates does for fish fibre what vegetables do for us — improving digestion and reducing bloat.
Surface feeders — paradise fish, danios, white clouds — take floating foods readily; watch that sinking pellets do not slip past them uneaten. Bottom specialists such as loaches, gudgeons and gobies need sinking tablets fed after the lights dim, when the fast swimmers are less competitive.
Bitterlings and other small cyprinids have tiny mouths; crush pellets for juveniles and observe that every individual is eating. A fish that hangs back at feeding time is usually the first visible sign of illness or bullying.
Color comes from carotenoids, which fish cannot synthesise — they must come from food. Spirulina, krill, and the carotenoids in brine shrimp and daphnia genuinely deepen reds and blues within a few weeks; no water additive does this.
Condition — the plump, firm muscle tone of a healthy fish — comes from protein and exercise. Higher-protein frozen and live foods two or three times a week, plus current in the tank that encourages swimming, build breeding condition faster than any single product.
Once or twice a day for adults, always an amount eaten within two minutes; juveniles growing toward adulthood can take three small feedings. Include one fasting day per week — it lets the digestive tract clear and mimics the irregular feeding of the wild.
Pellets, for most purposes: they sink at a controlled rate, retain water-stable vitamins longer, make portions easy to count, and pollute less because less dissolves uneaten. Use flake only for very small surface feeders that refuse pellets.
Because they are opportunistic feeders with no satiety signal adapted to captivity — in a stream, the fish that eats whenever food appears survives. Begging is a behaviour, not a need. Judge by body shape, not by the dance at the glass.
Feed sinking wafers or tablets just after lights-out, when competition from surface feeders drops. Place the food at the same spot each time — bottom fish learn the location within days — and remove anything uneaten by morning.
Yes. Live tubifex and bloodworm carry the double risk of overeating and introducing pathogens. Buy from clean sources, rinse thoroughly, feed amounts consumed in minutes, and treat live foods as a garnish — the staple should be a quality prepared food.