Pets
How much fish food should you feed your aquarium?
Daily flake or pellet grams from fish count and size — plus how long a jar lasts. Pair with the aquarium liters calculator.
Quick answer
Most aquarium problems blamed on “dirty water” start with overfeeding. Flakes and pellets that sink unused rot, feed algae and spike ammonia. The classic rule — only what fish finish in about two to three minutes, once or twice a day — is hard to turn into a shopping number. This calculator estimates grams per day from fish count and average size, then tells you how long a jar lasts so you stop guessing at the shelf.
Food per day
2 g
- Food per week
- 14 g
- Jar lasts about
- 50 days
Sizing the tank first?
Aquarium liters, heater and stockingRough guide for community freshwater tanks: about 0.1–0.55 g per fish per meal by size, finished in ~2–3 minutes. Uneaten food fouls the water — feed less if leftovers remain. Skip a day weekly if the tank is stable. Not for fry, marine or specialized diets. Not veterinary advice.
How it works
It is a planning aid for community tanks of small to medium fish, not a license to dump food. Skip feeding one day a week if the tank is stable; fry, predators and marine setups need different regimes. Pair portions with net tank liters from the aquarium calculator, and vacuum leftovers. Not a substitute for species-specific care sheets.
Frequently asked questions
How much flake food for 10 small tetras?+
Roughly 1–2 g per day total if you feed twice (about 0.1 g per small fish per meal). Watch the glass: if food hits the substrate after two minutes, you overdid it. A 100 g jar lasts about 1.5–3 months at that rate.
Flakes or pellets?+
Flakes suit surface feeders; sinking pellets suit bottom dwellers (corydoras, ancistrus). Many tanks use both. Grams are similar; density differs, so still use the two-minute rule.
Should I feed every day?+
Most healthy adult community fish do fine with one or two small daily feeds, and many keepers skip one day weekly. Never compensate a missed day with a double portion.
Does tank size change how much I feed?+
Stocking and fish size matter more than glass liters, but a small tank fouls faster if you overfeed. Size the tank first (aquarium calculator), then feed for the fish you actually keep.
As an Amazon Associate I earn from qualifying purchases — the price does not change for you.