Aquarium Fish Feed Quantity

Fish food quantity: the "2-3 minute rule"

The rule of thumb in the hobby is to feed only what the fish can finish in 2–3 minutes, twice a day. When flakes sink past them and settle on the substrate, that's the number one trigger for ammonia spikes, algae blooms, and dead biological filtration. A few reference points: Tetras, Bettas, Guppies take 1 pinch of flakes per meal; tropical community tanks run on 1–2% of the combined fish body weight per day; a fasting day once a week actually does adult fish good. No filter keeps up with the mess overfeeding creates. Example: in a 60 L tank with 6 neon tetras (2 cm each), one small pinch of flakes morning and evening is about right. Food left over after 3 min means you gave too much.

Practical applications

Beginner aquarists use it to sidestep the mistake almost everyone makes, which is overfeeding. It also helps during tank cycling, when extra food wrecks the biological filter and throws off the nitrogen cycle, and it's good for betta keepers trying to measure out those tiny portions or anyone sorting out vacation feeding. Brazilian aquarium clubs and lojistas (Cobasi, Petz) tell you to siphon leftovers every day, but feeding less beats cleaning more.

FAQ

My fish always look hungry — should I feed more? No. Most aquarium fish beg around the clock whether they're actually hungry or not. Stick to the 2–3 minute rule.

Can I skip a day? Sure. Adult fish handle 1 fasting day a week just fine, and it tends to do them good. Fry are the exception, they need feeding every day.

What if food reaches the substrate? Siphon it out right away and cut the next portion by 30%. Food that's left to rot pushes ammonia up within hours.

Flakes, pellets or live food? Mix it up. Flakes most days, frozen bloodworms 1–2x/week, the occasional batch of live brine shrimp. A varied diet keeps the nutritional gaps from opening up.