Bettas are carnivores that eat insects and small crustaceans in the wild, and they are notoriously easy to overfeed. This betta fish feeding guide covers what to buy, how much to give, how to build a weekly schedule with a fast day, and how to read the two problems that come from getting it wrong — a betta that won't eat, and one that is bloated.
What Do Betta Fish Eat?
Betta fish are carnivores with a strong preference for protein-rich live food. In the wild they eat insects that fall on the water surface, mosquito larvae, small crustaceans, and zooplankton. In the aquarium, a diet that reflects this — primarily protein-based with some variety — keeps bettas in excellent health and vivid colour.
Seriously Fish lists Daphnia, Artemia (brine shrimp) and chironomid larvae (bloodworm) alongside small insects as appropriate foods, and adds a warning worth repeating: take care not to overfeed, as Betta species seem particularly prone to obesity. Almost every feeding problem in this guide traces back to that one sentence.
Staple Food: Betta Pellets
High-quality betta pellets are the most practical staple for most keepers. They are nutritionally complete, easy to portion, and don't foul the water as quickly as some other foods.
How to read a betta food label
- Protein first: the first ingredient should be a whole fish or fish meal (salmon, herring, black soldier fly larvae) — not wheat, corn, or soy
- Minimum 40% crude protein on the guaranteed analysis
- Small pellet size: betta mouths are small; oversized pellets get taken and spat out repeatedly, which looks like fussiness but is a sizing problem
- Check the date: fish food oxidises. A tub that lasts a betta two years has lost much of its vitamin content by the end — buy the smallest container available
| Brand | Notes |
|---|---|
| Hikari Betta Bio-Gold | Widely available; good protein content; small pellet size |
| Fluval Bug Bites (Betta) | Black soldier fly larvae as primary ingredient; excellent nutrition |
| New Life Spectrum Betta | High protein; natural colour enhancers; well-regarded |
| Northfin Betta Bits | No artificial ingredients; high protein from whole fish |
Frozen & Live Foods
Supplementing pellets with frozen or live foods dramatically improves betta health, colour, and breeding condition. Feed these 3–5 times per week as variety, or as the primary diet for serious breeders.
- Frozen bloodworms: bettas go wild for them; excellent protein; do not overfeed — bloodworms are rich and can cause constipation if fed daily
- Frozen brine shrimp: excellent protein and natural colour enhancer; highly palatable
- Frozen daphnia: high fibre content; good for digestion; can help resolve mild constipation
- Frozen mysis shrimp: high protein; whole-prey nutritional profile
- Live food: flightless fruit flies, blackworms, micro worms, baby brine shrimp — exceptional for conditioning bettas before breeding
Thaw frozen food in a small cup of tank water rather than dropping the cube in whole. A whole cube is several days of food for one betta, and the melt water carries a heavy nutrient load straight into the tank.
How Much and How Often to Feed
Bettas have small stomachs — roughly the size of their eye. Overfeeding is one of the most common betta care mistakes and leads to obesity, swim bladder problems, and fouled water.
| Factor | Guidance |
|---|---|
| Frequency | Once or twice daily; twice is ideal for growth and condition |
| Portion size (pellets) | 3–5 small pellets per feeding; all consumed within 2 minutes |
| Fasting | Fast for 1 full day per week to prevent constipation and clear the digestive system |
| Remove uneaten food | Use a turkey baster or net to remove uneaten food within 5 minutes of feeding |
A workable weekly schedule
| Day | Morning | Evening |
|---|---|---|
| Mon, Wed, Fri | 3 pellets | 3 pellets |
| Tue, Thu | 3 pellets | Frozen bloodworm or brine shrimp (2–3 pieces) |
| Saturday | 3 pellets | Frozen daphnia (fibre) |
| Sunday | Fast day — no food | |
Cold water slows digestion, so if the tank runs below 76°F, fix the temperature before adjusting the diet. A betta that is not digesting properly at 72°F will not be fixed by feeding it differently.
Bloating, Constipation and the Fast Day
Signs of overfeeding are easy to read once you know them: a rounded or swollen abdomen, no visible faeces for three or more days, stringy white waste, and cloudy water within hours of feeding.
The standard response is to fast the fish for 2–3 days. If the abdomen is still distended, offer a small piece of blanched, shelled pea — bettas will usually take it, and the fibre helps clear the gut. Frozen daphnia works as well and is easier for the fish to eat.
Feeding Problems: Betta Won't Eat
A betta refusing food is a common concern. Work through these causes in order:
- New environment stress: newly purchased bettas often refuse food for 2–5 days while adjusting; wait and keep conditions stable
- Water temperature too low: below 74°F, betta metabolism slows and appetite decreases dramatically; check temperature first
- Food too large or wrong type: try a different pellet brand or crush pellets smaller; try frozen bloodworms, which are usually irresistible
- Water quality: test ammonia and nitrite before assuming the food is the problem — appetite is often the first thing to go when water quality slips
- Illness: persistent refusal combined with lethargy, clamped fins or unusual posture indicates illness rather than fussiness
- Overfeeding: some bettas go on short "hunger strikes" after being overfed; fast for 1–2 days
A betta that has eaten nothing for more than a week, or that is visibly thin along the belly, has moved past fussiness — see betta not eating and sunken belly.
Feeding While You Are Away
A healthy adult betta tolerates a short fast far better than it tolerates being overfed by a well-meaning neighbour. For trips of up to a week, the safest option is simply not to feed — bettas routinely go 5–7 days without harm, provided the tank is cycled and heated.
For longer absences, pre-portion pellets into a daily pill organiser for whoever is feeding, so there is no judgement call about quantity. Avoid the dissolving "vacation feeder blocks" sold for this purpose: they foul water in small tanks and bettas rarely eat them.
Frequently Asked Questions
What do betta fish eat?
Bettas are carnivores. A high-protein betta pellet is the practical staple, supplemented with frozen or live bloodworms, brine shrimp and daphnia. Seriously Fish lists Daphnia, Artemia and chironomid larvae as appropriate foods for the species.
How often should I feed my betta fish?
Once or twice daily, 3–5 small pellets per feeding, with everything eaten inside two minutes. Include one fast day per week. Remove uneaten food within five minutes so it does not decay in the tank.
Can betta fish eat tropical flake food?
Not as a staple. Most tropical flakes are formulated for omnivores and are heavy in wheat and soy filler, which does not meet a betta's protein requirement. Use a betta-specific pellet instead, and treat flakes as an emergency stopgap only.
Why won't my betta fish eat?
Most often the water is too cold, the fish is newly moved and still settling, or the pellets are too large. Check temperature first, then test ammonia and nitrite. Persistent refusal with lethargy or clamped fins points to illness rather than fussiness.
How long can a betta go without food?
A healthy adult betta can go 5–7 days without food in a cycled, heated tank, which is why a short holiday needs no feeder at all. Longer than that risks muscle loss, and the fish should not be fasted deliberately beyond a normal weekly fast day.
My betta looks bloated — should I stop feeding?
Fast for 2–3 days, then offer blanched shelled pea or frozen daphnia for fibre. If the scales are also protruding like a pine cone, this is dropsy rather than constipation, and fasting will not resolve it.
Sources and Editorial Method
Species diet and the obesity caution come from the reference cited inline. Portion sizes, the weekly schedule and holiday guidance reflect established aquarium practice rather than published research, and are presented as practical guidance rather than veterinary advice.
- Seriously Fish — Betta splendens: natural diet items and the warning that Betta species are prone to obesity.
- PetMD — Betta fish facts and care: veterinarian-authored overview of feeding and husbandry.