How Much to Feed Fish per Day

I used to think “a pinch” meant “a healthy amount.” It didn’t. My tank looked fine… until I started getting cloudy water, algae, and rising nitrates. The fix wasn’t a new filter—it was feeding less, watching what actually gets eaten, and being honest about leftovers.

1) The 3 rules that keep beginners out of trouble

Rule #1: The tank decides the portion (not the label)

Fish food labels are a rough starting point, but your aquarium is the real judge. Aqueon’s guideline is simple: feed only what fish can consume in 2–3 minutes, start with a tiny amount, and adjust. They also recommend removing uneaten food if it remains. Aqueon feeding guide

Rule #2: “Once a day” is the safe default for most tanks

For most beginner community tanks, once per day is a safe baseline. Aquarium Co-Op notes most fish are fine with being fed once a day, and if you prefer, you can do two smaller meals for enjoyment (still small portions). Aquarium Co-Op feeding frequency

Rule #3: When in doubt, underfeed (new tanks especially)

Aqueon explicitly points out that it’s best to underfeed, especially in new aquariums, because uneaten food can cloud water and contribute to dangerous water-parameter problems. Aqueon feeding guide

2) The 2–3 minute method (and why it works)

This is the method I recommend to new fishkeepers because it doesn’t require a scale, a calculator, or guessing fish body weight. It’s just observation.

1. Feed smaller than you think. Add a tiny amount first.
2. Start a timer. Watch the fish eat for 2 minutes.
3. Stop at 2–3 minutes total feeding time. If food is still floating/sinking, reduce next time.
4. Check the bottom. Food sitting on the substrate is the clearest “too much” signal.

This aligns with Aqueon’s “2–3 minutes” rule of thumb and the “start tiny and observe” approach. Aqueon feeding guide

How “2–3 minutes” looks for different foods

3) Starter portions by tank size (practical numbers)

Important These are conservative starting points. Your goal is still: no leftovers and food consumed within ~2–3 minutes. Aqueon feeding guide

4) Adjust by fish type (this is where beginners accidentally overfeed)

Surface feeders vs midwater vs bottom feeders

Aqueon notes that some fish feed at the surface while others feed on the bottom, and shy fish may need target-feeding. Aqueon feeding guide

• Surface/midwater fish often dominate floating food.
• Bottom feeders (corydoras, loaches, many catfish) do best with sinking foods and may need feeding when lights are out.

Goldfish

Goldfish are waste machines. If you keep goldfish, keep portions small and avoid “constant snacking” unless you are doing very frequent maintenance. When in doubt, use the same principle: small portions, no leftovers.

Bettas

Many bettas will eat until they’re bloated if you let them. The safest beginner approach is small pellet counts and a consistent routine.

Fry (baby fish)

Fry are the big exception—many tiny feedings are normal because they grow fast and can’t eat big meals. The key is still: tiny portions, and keep water quality high.

5) Overfeeding vs underfeeding: what it looks like (and what it does)

Overfeeding (most common beginner mistake)

The Spruce Pets warns that overfeeding can lead to several aquarium problems and can increase ammonia/nitrite/nitrate while lowering oxygen and pH. They also emphasize keeping feedings very small. The Spruce Pets

Underfeeding (usually safer short-term)

Short-term underfeeding is usually easier to correct than overfeeding. Fish begging at the glass is not proof they need more—fish often eat opportunistically when food appears. The Spruce Pets notes fish will eat whenever they have a chance and can “beg” even when not in dire need. The Spruce Pets

6) If you overfed today: the 15-minute rescue plan

1. Stop feeding immediately (don’t “balance it out” with more).
2. Remove visible leftovers with a net or siphon.
3. Do a partial water change if the water clouds up or smells off.
4. Increase aeration (extra surface agitation / air stone) if fish are stressed.
5. Fast 24 hours, then resume at half portions for 3 days.

7) Vacation feeding (1–14 days)

The Spruce Pets notes healthy adult fish can often go a week or two without feeding, while young fish can’t go without eating for very long. The Spruce Pets vacation feeding

• 1–7 days: Most healthy adult fish are fine with no food (don’t “pre-feed” extra).
• 8–14 days: Pre-portion food and have someone feed 2–3 times per week (tiny amounts).
• Fry tanks: Arrange a sitter or a reliable plan—fry are the exception.

8) FAQ

How much should I feed fish per day?

Use the 2–3 minute rule: feed only what they fully consume in 2–3 minutes, once daily for most tanks. Aqueon feeding guide

Should I feed once or twice a day?

The Spruce Pets states many fish do well with one or two feedings per day, but the key is to keep feedings very small. The Spruce Pets

My fish act starving—am I underfeeding?

Not necessarily. The Spruce Pets explains fish are opportunistic and will often eat whenever food appears—even if they don’t truly need it. Begging is not a reliable hunger signal. The Spruce Pets

What if food always sinks to the bottom?

That usually means portions are too large, food size is wrong, or timing is wrong. Reduce the amount and consider smaller pellets or feeding in multiple spots so it doesn’t all fall in one pile.

How do I know if I’m overfeeding?

The Spruce Pets lists uneaten food near the bottom and high nitrates as clear signs of overfeeding, and warns overfeeding can pollute the water and clog filters. The Spruce Pets