Caring for Halfmoon Betta Fish: Diet, Water Conditions, and More

Halfmoon betta’s natural environment is the same as many other betta species.

They hail from Southeast Asia and were not originally a result of captive breeding.

Today, they are sought after for their uniquely beautiful tail structure.


halfmoon betta atf

The halfmoon’s elaborate tail is the key to its distinctive look.

A betta is only a halfmoon if they have a 180-degree tail flare, giving the appearance of a crescent moon.

They come in all kinds of colors and patterns. You’ll find red, blue, green, orange, yellow, even black or purple.

Their tail structure sets them apart from other betta fish with these common patterns.

Unique Concerns

Halfmoons have large, flowing fins and tails. This means the risk of fin or tail rot is heightened.

We don’t ever want sharp or rough objects in the same space as our aquarium fish.

But with halfmoons, it is essential to sand down any rough edges.

If you don’t use real aquarium plants, get soft silk rather than plastic. 

It’s all too easy for your betta to get caught on something sharp or pointy and tear their fins.

This leaves them open to bacterial infections and fin rot, two of these freshwater fish’s more common health issues.

Fortunately, these problems are curable in most cases. Do regular checks of your halfmoon to make sure they are unharmed.

Catching injuries and illnesses quickly really raises your chances of successful treatment.


The average lifespan for a halfmoon betta is 2-3 years.

Some live longer, occasionally even reaching 5 years of age. But this is rare, so don’t count on it.

To ensure your pet lives as long as possible, keep them in optimal water conditions.

This means following proper water parameters, keeping chemical levels down, and giving them a comfortable environment.

One of the most common reasons betta fish die is they are forced to live in poor water conditions.

Average Size

The standard size for a halfmoon betta is 2.5-3 inches or 6.4-7.6 centimeters long.

In other words, they grow to be about the same size as other adult Siamese fighting fish.

Their tails are significantly larger than some breeds, though. This may make them appear longer than other bettas.

Halfmoon Betta Care

halfmoon betta fish care

Halfmoon betta fish are one of the easier betta varieties to care for.

They don’t require special treatment outside the usual precautions we take for betta fish.

Tank Size

The standard rule applies to halfmoon betta fish. They need 5 gallons of space per fish.

You won’t be filling the tank to the top.

Betta fish have a labyrinth organ which allows them to breathe air from the surface and deriving it from the water.

They’re also exceptional jumpers and are very much capable of leaping out of an uncovered tank.

Keep the water level well below the rim of the aquarium.

With 5 gallon, they have ample space to exercise and explore. This helps prevent boredom, provide stimulation, and overall make your halfmoon happier.

Water Parameters

Basic betta fish care guidelines apply to the halfmoon.

They’re tropical fish who like neutral soft water.

Here’s a complete list of water parameters:

Ideal Water Parameters for a Betta Fish Tank Include the following:

  • Temperature: 78-80° degrees Fahrenheit (25.5-27° C)
  • pH: 6.5-7.5
  • Ammonia and Nitrite: 0 ppm
  • Nitrate: < 40 ppm
  • gH: 3-4 dGH (50-66.7 ppm)
  • kH: 3-5 dKH (53.6-89.4 ppm)
  • Minimum Tank Size: 5 Gallons

Following the proper water parameters is important to all varieties of freshwater fish.

But it’s more critical for the halfmoon, because their bodies are more sensitive. 

What To Put In Their Tank

The primary concern is you need to be careful to protect their flowing, distinct tails. No sharp or rough objects go in this betta’s tank.

This is, of course, a rule of thumb we use for all varieties of betta splendens.

With this in mind, your betta needs lots of plants and caves to hide.

Aside from emulating the betta’s natural habitat, plants are good at absorbing harmful chemicals from the aquarium water.

Some aquatic plant species lower ammonia levels, which is critical to maintaining good water quality.

Floating plants and planted ones are both wonderful and come with unique benefits.

It’s fascinating how much of a difference plants make for your betta.

If you want to read up on why they’re so important, here’s our article on keeping a planted tank.

Keeping a wide range of decor is fun for both you and your pet.

It’s best if you actually have extra pieces to rotate between as you do water changes. This keeps your betta engaged with its surroundings.

I personally love driftwood, floating logs, and caves made to look like rocks or wood.

They mimic the betta’s natural environment, for one thing. But they’re also adorable!

Aside from decor and plants, remember the essentials:

  • Light with timer
  • Heater and thermometer
  • Gentle filter

These are your aids in keeping the water quality stable.

Small things like slightly colder water or pH changes can really do a number on your halfmoon.

Remember, their tails and fins are more vulnerable to environmental dangers.

Possible Diseases

Halfmoon betta fish are susceptible to the usual betta plights:

  • Fin rot
  • Swim bladder disease (SBD)
  • Dropsy
  • Bloat
  • Constipation
  • Bacterial infection
  • Fungal infection
  • Parasites

This is a long list, but these health issues are preventable!

The most important here is fin rot, which poses even more of a threat to halfmoons.

Because their tail and fins are so long, the halfmoon is more likely to be injured by decor or tank mates.

Once injured, it’s very easy for a betta to develop an infection. The trick to avoiding this is keeping a hospital tank filled with clean water.

Some of the cures for common ailments include aquarium salt, Melafix, Pimafix and Methylene Blue.

Above all, we recommend taking preventative measures. 

Water conditioners like this one are designed to help boost betta immune systems.

Using a conditioner with immune system boosters in it is easy enough to do every time you perform a partial water change.

Simple, but essential!

Food & Diet

halfmoon betta fish diet

 Like other bettas, the halfmoon needs a high-protein diet of betta pellets supplemented with live and frozen foods.

You must pick the right commercial fish food as not all of them are suitable for betta fish.

Choose pellets specifically geared toward betta splendens and other choices of aquarium fish who eat high-protein diets.

The best way to combine frozen, live, and commercial pellets is to outline a weekly feeding schedule.

Many betta keepers pick one day a week to fast their betta. This is not necessary, but it does help prevent bloat and constipation in some fish.

Always plan on a balanced diet. Feeding pellets once a day and live or frozen foods once a day is a great way to satisfy your pet.

First of all, they are sure to get a high-protein diet and feel great.

But they’ll also look forward to feeding periods because they know they get to hunt for live food. Or at least they know they aren’t eating the same thing all the time.

You might not be familiar with some frozen and live food options for betta fish.

Commercial pellets are easy to come by, and some pet stores don’t take the time to suggest other feeding habits.

If you want to see a list of some great betta treats and meal options for your halfmoon, here’s an article for you.

It’s amazing how much variety your betta can actually have!

Behavior and Temperament

 Halfmoon betta fish are pretty typical in terms of temperament and behavioral problems.

Remember, people used to raise betta fish for fighting purposes.

Even when they have adequate space, they tend to act very territorially. This is one reason they don’t tend to like living with other fish.

The halfmoon is no different. 

You might find one with a more docile personality. But they still have those territorial instincts.

Tank Mates

To speak generally, the halfmoon betta is more of a solitary fish. They like having ample space all to themselves.

 Still, you have some viable options for tank mates.

The halfmoon, like other betta fish, does well with snails and some shrimp species.

With a particularly calm and social halfmoon, you might even pair them with a peaceful freshwater fish.

Do not put two betta fish together. The only case where this is suggested is for a breeding tank or a betta sorority.

The latter, though, is an endeavor for experienced betta keepers.

Here are some species of shrimp, snails, and a couple of fish you might pair with your betta:

  • Cherry shrimp
  • Ghost shrimp
  • Nerite snails
  • Mystery snails
  • Tetras
  • Kuhli loaches

Every time you add a new critter to the tank, be observant.

We suggest you use a tank divider or floating breeding box to first introduce your betta to their new friend.

You might have to pull the plug if you see a lot of flaring, charging, or attempted nipping.

Keep in mind, too; tank mates may have different needs. The betta likes a high-protein diet, for example.

But many snails and shrimp are algae-eaters. They are mainly able to get a balanced diet just by cleaning up food waste and algae in the betta fish tank.

Breeding Halfmoon Betta Fish

The first step to breeding halfmoon bettas is to find your breeding pair.

It’s best to use fairly young but sexually mature betta fish. 4-12 months gives you the greatest chance of success.

Set up a breeding tank complete with a filter, plants, decor, and some sort of floating log or floating plant.

The floating structure is where the male betta builds the bubble nest.

Keep the male and female separate until the bubble nest phase, as they might be aggressive toward one another beforehand.

Once the bubble nest is complete, the female betta inspects it.

If it pleases her, the two fish mate.

How Much Does a Halfmoon Betta Cost?

halfmoon betta cost

Halfmoon bettas are generally priced at $30-40. 

This is certainly higher than some varieties. But they’re a sought-after elegant fish, so it makes total sense.

You might see higher fish prices for the rare betta fish colors.

For example, purple is an exceedingly rare find, even when combined with other colors. A purple halfmoon, if you miraculously found one, might be priced at $80 or even more.

Are Halfmoons Rare?

Halfmoon betta fish are not rare, per se. But they are valuable.

They’re some of the most beautiful, coveted breeds of betta fish you’ll find. As such, they go fast when made available in pet stores.

Still, it isn’t too hard to find a halfmoon betta for sale. They are regularly stocked at many chain pet stores.

Halfmoon Betta FAQ

Are halfmoon bettas less aggressive than other varieties?

The halfmoon betta is prone to the same aggressive tendencies as other betta varieties. Still, it’s very possible to find a friendly and calm halfmoon betta.

At a pet store or breeder’s, look for the halfmoon who rarely flares or charges. If they have tank mates, observe how they interact with them.

The fewer aggressive behaviors you see, the more likely this betta is a sweetheart. Look out for signs of stress or illness as well. A temperamental betta might act docile when sick.

A healthy fish swims around a lot, eats readily, and makes trips to the surface for air sometimes.

Find a healthy fish who shows few signs of aggression, and your halfmoon may very well be more docile than other betta fish you’ve encountered.

Is there a double-tail halfmoon betta?

Double-tail halfmoon betta fish are harder to find than ordinary halfmoons.

Finding both types of bettas needed for breeding purposes is tough. You need a double-tail and a halfmoon betta, both of which are popular varieties.

The double-tail is difficult to breed, because of their shorter body type. Double-tail betta fish are also more sensitive to certain fish diseases like swim bladder disorder (SBD).

Double-tail halfmoon betta fish are prone to similar problems, beautiful as they may be.

Can halfmoon bettas live with other fish?

It is technically possible to keep a halfmoon with another fish species. We do not recommend doing this, though.

For one thing, their tail and fins are more vulnerable to common infections if they get nipped. Even peaceful fish sometimes get aggressive if stressed out for any reason.

The halfmoon may also get aggressive with the fish you add to their space. Betta fish are territorial. Sometimes this is even true in very large aquariums.

The safest option is to keep your betta swimming solo, or to get them snails or shrimp to live with.

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Jacinta was raised on a dairy farm in Vermont where they worked extensively with cows, chickens, pigs, goats, and other animals. They have a background in writing both creatively and professionally.

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