Betta Fish Food UK Guide: What to Feed, How Much & a Simple Weekly Plan

Betta fish food advice online is often vague: “feed pellets, don’t overfeed, give bloodworms as a treat.”

That’s not enough for beginners in UK homes, especially those running common 20–40L tanks where overfeeding quickly turns into water quality problems, constipation, and stressed fish. The same feeding principles apply just as much in larger aquariums, too.

Bettas are carnivorous insect-eaters, and their diet should reflect that. With the right staple food, realistic portions, and a simple feeding schedule, you can follow without guessing.

This guide shows you what to feed your betta, how much, how often, and how feeding directly affects water stability in UK tanks. 

We focus on what actually makes the best betta food in the UK: ingredients, protein level, and pellet size, not marketing claims on the packaging.

Quick Answer: What should I feed my betta, and how often?

• Main food: high-protein betta pellets (daily staple)
• Meals: 1–2 very small meals per day
• Fasting day: once per week
• Treats: frozen/live foods 2–3× per week (not daily)
• Freeze-dried: only if soaked first

If you follow just this, you’ll avoid most common feeding problems.

Quick navigation:

• What do bettas eat in nature?
• Types of betta food (pros, cons, when to use)
• How to choose a good betta pellet (UK shop reality)
• How much to feed a betta (portions that actually work)
• Simple weekly feeding plan (20–40L UK tank)
• Betta fish food and water quality in tanks of any size
• When your betta won't eat or has feeding problems
• Common feeding mistakes to avoid
• FAQ
• Conclusion

What do bettas eat in nature? (And why it matters)

Bettas are carnivorous insect-eaters. In the wild, they feed on insect larvae, small crustaceans, and other tiny invertebrates found at the water surface.

This is why their diet in aquariums should be based on high-protein foods rather than flakes or plant-heavy formulas designed for community fish.

You can read more about bettas' natural insect-based diet here.

Types of Betta Food (Pros, Cons, When to Use)

Because bettas are carnivorous insect-eaters, your goal is to feed foods that match this natural diet while keeping portions easy to control. 

What are pellets and flakes?

If you’re new to fishkeeping, these terms can be confusing.

• Pellets are small, round or oval pieces of dry food. They sink slowly and are easy to feed one at a time. Most betta foods come in pellet form.
• Flakes are thin, flat pieces that float on the surface and break apart easily. They are commonly used for community fish, not carnivorous bettas.

Pellets are easier to portion, cleaner for the water, and much better suited to bettas' eating habits.

Pellets (daily staple)

High-protein betta pellets should be the foundation of the diet.

They are:

• Formulated for carnivorous fish
• Easy to portion correctly
• Nutritionally balanced for daily feeding

Good pellets make feeding simple and predictable. The best pellets are usually insect-based or shrimp-based micro-pellets designed for carnivorous fish.

Frozen/live food (protein boost & enrichment)

Bloodworms, brine shrimp, and daphnia are excellent as occasional treats.

They:

• Provide enrichment and variety
• Encourage natural hunting behaviour
• Add extra protein to the diet

But they are not suitable as daily food, especially bloodworms, which are quite fatty. 

Daphnia is especially useful for digestion and is often recommended when a betta shows signs of constipation or bloating.

Freeze-dried (only if soaked)

Convenient to store, but risky if fed dry.

When dry, these foods expand inside the stomach and frequently cause bloating. Always soak them in tank water for 10–20 seconds before feeding.

Best used rarely. 

Flakes (usually a poor choice)

Most flakes are designed for community fish, not carnivorous bettas.

They:

• Contain fillers and plant matter
• Break apart easily and pollute the water
• It's hard to portion correctly

Bettas can eat flakes, but pellets are far better suited to their needs. 

How to Choose a Good Betta Pellet (UK Shop Reality)

When you’re in a UK shop looking at betta food, ignore the marketing on the front of the pack.

Turn it around and read the ingredients. That’s where the truth is.

The first 3 ingredients rule

The first ingredients should be animal-based protein, such as:

• Fish meal
• Shrimp meal
• Insect protein

If you see wheat, cereals, or plant fillers listed first, it’s not ideal for a carnivorous betta.

Look for food with 38–45% protein. Lower than this usually means more fillers and less nutrition.

Pellet size matters more than you think

Many beginners buy pellets that are too large.

Large pellets often cause:

• Bettas spitting the food out
• Swallowing difficulties
• Constipation and bloating

Micro-pellets are much easier for bettas to eat and digest.

Signs of low-quality food

You can often tell the quality of betta pellets just by checking a few simple details:

Good betta pellets	Poor quality pellets
Fish/shrimp/insect protein first	Wheat or cereals listed first
38–45% protein	Low protein, high fillers
Small micro-pellet size	Large, hard pellets
Dark colour, compact	Pale colour, dusty
Neutral smell	Strong cereal smell

Good betta pellets are compact, darker in colour, and don’t crumble easily.

Quick checklist when choosing betta pellets

If the food has:

• Animal protein is the first ingredient 
• 38–45% protein
• Small pellet size
• Minimal dust in the pack

It’s likely a good choice for daily feeding.

How Much to Feed a Betta (Portions That Actually Work)

Overfeeding is the number one feeding mistake beginners make. Bettas need far less food than most people think. 

These portion guidelines apply to one adult betta and do not change based on tank size. A larger aquarium does not mean the fish needs more food.

The “size of the betta’s eye” rule

A betta’s stomach is roughly the size of its eye. That’s the amount of food per meal.

This rule works regardless of tank size.

Adjusting for pellet size

Pellets come in different sizes, so the number matters less than the total volume.

• Small micro-pellets: 3–5 per meal
• Larger pellets: 2–3 per meal

If the betta struggles to swallow or spits food out, the pellets are too large.

1 meal vs 2 meals per day

Two small meals are better than one larger meal because:

• Easier digestion
• Less waste in the water
• More natural feeding pattern

Feeding less in cooler rooms

In cooler UK rooms (below 24°C), a betta’s metabolism slows down.

Feed slightly less during colder periods, especially in winter.

A simple test: are you feeding too much?

If you notice:

• Uneaten food after 1 minute
• A slightly swollen belly after feeding
• Increased waste at the bottom of the tank

You’re feeding too much. Very small portion sizes are recommended for bettas.

Simple Weekly Feeding Plan (20–40L UK Tank)

A simple rotation makes feeding easy, prevents overfeeding, and gives your betta a balanced diet without you having to guess each day.

Why this plan works

• Pellets provide stable daily nutrition
• Frozen food adds variety without excess fat
• A fasting day prevents constipation and bloating
• The schedule is easy to remember and repeat every week

You don’t need to invent a new feeding routine, just follow this cycle.

Does this apply to larger aquariums, too?

Yes. Even in bigger tanks (60L+), the portion size stays the same.
The goal is still small meals, variety, and one rest day for digestion.

Betta Fish Food and Water Quality in Tanks of Any Size

Overfeeding is the fastest way to ruin water quality in a betta tank.

This happens especially quickly in common 20–40L setups, where water reacts to mistakes within hours rather than days. Still, the same issue can affect larger aquariums, too, if portions are not controlled. 

If you’re unsure what tank size your betta should be in, see our UK tank size guide in litres.

Why do extra pellets cause ammonia fast?

Uneaten food sinks to the bottom and begins to break down.

This creates:

• Ammonia spikes
• Cloudy water
• Stressed fish
• Extra work for your filter

What looks like “just one extra pellet” can destabilise the tank surprisingly fast.

Feeding lightly in newly cycled tanks

In newly set-up tanks, beneficial bacteria are still stabilising.

For the first 2 weeks:

• Feed slightly less than usual
• Avoid treats
• Remove any uneaten food immediately

This helps the tank settle properly. If you’re not sure whether your tank is fully cycled, follow our UK betta tank cycling guide.

Feeding correctly is part of keeping water stable

Proper feeding is as important as:

• Filtration
• Heating
• Cycling

It’s all connected.

Feeding in larger aquariums (60L+)

In larger tanks, water is more forgiving, but the same feeding rules apply.

Overfeeding still pollutes the water, just more slowly.
Portion size should always be based on the betta, not the tank size.

When Your Betta Won't Eat or Has Feeding Problems

Feeding problems are very common with bettas, especially in the first weeks. Refusing food, spitting pellets, or signs of bloating usually come from portion size, pellet size, or recent stress.
These quick fixes solve most feeding issues without needing medication.

Betta spits pellets or refuses food

• Try smaller pellets
• Soak pellets for 10 seconds before feeding
• Skip feeding for 24h, then try again

Constipation and bloating (very common)

• Stop feeding for 1 day
• Offer daphnia the next day
• Avoid freeze-dried foods

Feeding after shipping, stress or with older bettas

• Feed very lightly for the first 2 days after shipping
• Older bettas: feed once per day, smaller portions
  

Common Feeding Mistakes to Avoid

Most betta feeding problems don’t come from the wrong food; they come from small mistakes repeated every day.

Feeding bloodworms every day

Bloodworms are very fatty and should be given only as occasional treats. Daily feeding often leads to obesity and bloating.

Not soaking freeze-dried food

Freeze-dried foods expand when wet. If fed dry, they expand inside the stomach and frequently cause constipation.

Always soak them in tank water for 10–20 seconds first.

Leaving food in the tank

Uneaten food breaks down quickly and pollutes the water. Remove anything the betta doesn’t eat within a minute.

“Grazing” all day

Bettas are not grazing fish. They should eat small meals and not have food available all the time.

FAQ

What type of food is best for betta fish?

High-protein betta pellets should be the staple diet. They are easy to portion and designed for carnivorous fish. Frozen foods like bloodworms or daphnia can be used occasionally as treats.

How often do you feed a betta?

Feed 1–2 very small meals per day and include one fasting day per week. Small, controlled portions are far more important than feeding frequency.

How long can a betta go without eating?

Healthy adult bettas can go 3–5 days without food if necessary. Short fasting periods are not harmful and can even help digestion.

Can bettas eat flakes?

They can, but flakes are made for community fish and often contain fillers. Pellets are much better suited to a betta’s diet and are easier to portion correctly.

Do bettas need live food?

No. Bettas can thrive on quality pellets alone, but occasional frozen or live food provides enrichment and dietary variety.

Can bettas eat mosquito larvae from outside?

It’s not recommended. Wild larvae may carry parasites, bacteria, or pollutants that can harm your fish.

What is the best betta food available in the UK?

Look for micro-pellets with fish, shrimp, or insect protein listed as the first ingredients and a protein content of around 38–45%.

Conclusion

Feeding a betta correctly is not complicated, but it does require consistency.

A diet built around high-protein pellets, tiny portions, a simple weekly routine, occasional treats, and one fasting day prevents the most common problems before they start: bloating, constipation, and poor water quality.

These feeding principles apply whether your betta lives in a 20–40L beginner tank or a larger aquarium. Portion control and food choice always matter more than tank size. 

This guide assumes you are feeding a single betta. If you keep other fish in the aquarium, adjust feeding so no food is left uneaten.

For a setup that supports proper feeding and long-term water stability, read the Betta Tank Setup UK guide and the Betta Care UK guide.