Betta splendens is one of the most popular aquarium fish in the world. Originally from Southeast Asia, Bettas are a sub-group of fish within the larger Osphronemidae family, which includes the diverse and attractive Gouramis.
There are several wild Betta species but they are very uncommon save in specialist aquarium stores. Some are much larger and a few are even peaceful and can be kept in groups.
Betta Fish are popular because their care requirements are about as easy as it gets for tropical fish. They tolerate a wide range of temperatures, water conditions, food offerings, and mistakes first time fish keepers make. They are also disease resistant, inexpensive, and come in a wide variety of colors.
Note that nearly every Betta Fish you’ll come across in pet stores is a male. Male Bettas have long, flowing finnage full of color that make them popular. Female Bettas are usually special orders for hobbyists trying to breed them because they are smaller and have some color in their fins but aren’t nearly as bright.
- Scientific Name: Betta splendens
- Origin: Southeast Asia
- Size: 2 to 3 inches
- Temperament: Good Community Fish but Territorial Towards Other Bettas
- Difficulty: Very Easy
- Ease of Breeding: Moderate
Betta History in the Aquarium Trade
Betta Fish, also known as Siamese Fighting Fish or simply Bettas, have a long history in their home region and particularly the Kingdom of Thailand or Siam.
Local people would collect Betta Fish from ditches, rice patties, and streams, knowing that the males are territorial and will fight when placed together. The ability of Betta Fish to breathe air allows them to survive in stagnant bowls and jars with ease.
As they became more popular, locals began breeding Betta Fish for color, finnage, and aggression. Wild Betta Fish are territorial but never murderous. Captive bred Betta Fish are the result of generations of selective breeding and will fight until one fish flees – or dies of exhaustion.
When you visit your local pet store to choose a Betta Fish, when you look upon the rows of glass bowls take a moment to notice how the individual Bettas react to each other.
You want to choose a male that’s vigorously trying to get at his neighbor – not because you want to fight them but because he’s healthy and not likely to be drained by lack of food or poor water quality. Bettas listlessly hanging at the surface with closed fins should be avoided, even if that’s every Betta Fish in the store.
What Size Aquarium Should I Use for My Betta?
This question always comes up, regardless of the kind of fish you have in mind. And the answer is always the same: you should buy a tank as large as you can afford and have space for.
Bowls are not suitable for Beta fish!
The reason is very simple and is tied into water quality: smaller bodies of water will shift in conditions much quicker than larger ones. If I overfeed my Betta in a 20 gallon tank it will not immediately impact ammonia or nitrite levels unless I dump half the can into the water.
Overfeeding a Betta in a 2 gallon tank is much more likely to cause a rise in ammonia levels. And if I don’t have a filter colonized by beneficial bacteria to break down that ammonia, my Betta Fish is in for a rough ride.
If the power goes out a 2 gallon tank will get cold faster than a 20 gallon tank will. Smaller bodies of water undergo lethal shifts quickly. Also, extra space means extra room for companions, should you decide to make it a community tank!
Sometimes all we have space for is that 2 to 5 gallon bowl or tank. In that case, a Betta is still a good choice. However we should be providing either a mini-heater or choosing a space in our home where the temperature won’t fluctuate too frequently.
Window sills are some of the worst places for Betta bowls and tanks because the Sun will heat the tiny tank very quickly. It will also cool rapidly at the end of the day, both of which can cause stress and illness. Choose a place without much change in lighting or temperature.
Water Conditions for Bettas
Maintaining water quality is one of the greatest aspects of Betta Fish care. They are extremely easy to keep happy and healthy and tolerate fluctuations that would kill other fish because in the wild they live in shallow ponds that shift in temperature and other conditions quickly and frequently.
That being said, Bettas do have preferences that, when followed, will ensure you get great color and optimal health.
- pH: acidic to neutral
- Temperature: 70-80F
- Hardness: >25 dH
- Ammonia, nitrite, nitrate: 0ppm
Betta Fish will live in hard, alkaline water, temperatures below 70F, and higher levels of ammonia, nitrite, and nitrate. However, we want to be providing the best possible conditions for our fish.
Most tap water is neutral to slightly alkaline. The mineralization improves the taste and causes few issues other than lime buildup in plumbing. Betta Fish prefer water with little mineralization and a pH of less than 7 (neutral). Aquarium stores carry several chemical agents that help adjust the parameters when doing water changes to suit your Betta’s preferences!
Betta Fish Care Tools
Monitoring water quality is an important aspect of Betta Fish care. Since Bettas aren’t as sensitive as other fish I don’t use liquid test kits because, while more exacting, they aren’t really necessary. 6-in-1 test strips like these give great results with minimal effort! Ammonia uses a separate kit because the reagents are reactive with the others. Or, you can use a simple in-aquarium Ammonia Meter for continual monitoring of water quality.
A heater is best as well because chilled Bettas have weakened immune systems and are far more likely to contract ich, dropsy, and other foul water illnesses. How strong a heater you need depends on the volume of your tank – 2.5 to 5 watts per gallon is the standard most aquarists use.
Betta Fish are tolerant of room temperature conditions but are tropical fish and prefer temperatures from 70-80F; the warmer the better. When using a heater you’ll also want a thermometer for exact temperature readings at all times.
A sponge or submersible filter is also ideal for providing an easy to clean unit that houses beneficial bacteria once your bowl or aquarium cycles. Nitrifying bacteria are a major part of aquarium care. For a quick summary of the process: your fish eats food and creates waste much like any other animal.
This nitrogenous waste contains organic molecules and ammonia. Both are broken down by specialized aquatic bacteria to form less toxic compounds. However, these bacteria need a home to colonize or their numbers will always remain low. The filter provides both water movement and a home base for your nitrifying bacteria!
The smaller the tank the more important filtration is. Many first time Betta keepers end up buying a bowl with a plant, thinking the plant provides filtration. However, that’s not the case. If you want to read more about Betta Bowls and filtration, I cover the topic in greater detail here!
Another easy aspect of Betta Fish care is feeding. Having been captive bred for decades Bettas will accept anything small enough to fit in their tiny mouths. Betta Fish pellets and flakes are the usual fare. Freeze dried bloodworms are a treat that doesn’t need refrigeration and is happily accepted for a bit of diversity.
If kept in community tanks make sure you keep an eye on your Betta so he gets his share. They can be delicately slow eaters at times and easily outcompeted by speedier fish like tetras and barbs.
As a rough rule of thumb, for smaller fish their stomach is about as large as their eye so you want to be offering enough food to fill that volume. If your fish eats a little more or less than that at a given meal that’s entirely fine.
Enriching your Betta Fish’s diet with frozen and live foods is something I highly recommend. Not only will your Betta appreciate it but carotenoids and other pigments taken from brightly colored food like Bloodworms and Tubifex are turned into fin and body pigments, enhancing reds, yellows, and golds in your Betta.
Other great frozen and live foods include baby and adult Brine Shrimp, Daphnia, and wingless fruit flies, most of which can be purchased in specialty aquarium stores. These unprocessed foods offer roughage from hard shells and extra nutrients from their pre-digested gut contents.
Can Bettas Be Kept With Other Fish?
Absolutely! Betta Fish are famously aggressive towards one another but mostly ignore their tank mates.
Mostly. Fish that have long flowing fins like Fancy Guppies and Lyretail Mollies may be chased because your Betta sees them as a possible competitor. However Betta Fish are poor swimmers compared to most fish and will rarely be able to catch and bite the offender. I discuss the most compatible Betta Fish Tank Mates here!
Great Tank Mates for Bettas:
- Danios and Rasboras
When looking at community fish your main concern should be more about whether they can cause your Betta Fish harm or not. Bettas are slow swimmers with flashy, constantly waving fins that are very tempting for fin nippers.
Barbs, larger Tetras, and Dwarf Cichlids may take a chunk out of the fins of an active Betta, leaving wounds for infection and stressing the Betta in the process. Predatory fish should also be avoided; large Cichlids and Catfish can eventually grow large enough to make a meal out of your Betta!
Poor Tank Mates for Bettas:
- Large Tetras
- Large Catfish
- Freshwater Sharks
- Other Bettas
Knowing precisely how many fish you can add to your bowl or aquarium can be tricky when first starting. The common rule of “one fish per gallon” is often repeated even by pet store employees who should know better. Use my discussion on How Many Fish Per Gallon to choose the right size and number of tank mates for your Betta!
Keeping Male Bettas Together
Believe it or not, you can keep male Bettas together! It just takes a bit of planning to pull off. Keeping two male Betta Fish in a small bowl or tank will result in one or two dead Bettas. However if you keep multiple males in a spacious aquarium with plenty of breaks in line of sight, Bettas can live together in relative harmony.
A good rule of thumb is one male per 10 gallons and never less than four males. This allows them to spread their aggression out across the group, rather than a single male becoming the outcast and getting constantly harassed.
This necessitates an aquarium of 40+ gallons replicating their natural habitat: full of aquatic plants that fill the surface and middle water column like Hornwort, Vallisneria, and Elodea. These plants provide territorial markers and hide the Bettas from one another so they aren’t on full alert constantly.
While they will still display and spar this way their bouts are far less frequent and rarely deadly because the loser can actually leave the territory of the winner. Providing one female per male also helps take their attention away from one another and towards building bubble nests and displaying for potential mates.
Breeding Betta Fish is one of the most satisfying projects you can undertake! It means you’ve not only mastered providing good water quality but you also fully understand Betta behavior, life cycles, and are prepared to raise the next generation!
As mentioned earlier male Betta Fish are larger, more colorful, and have longer fins. When you find a female Betta the differences will be immediately obvious. Females are also slightly stockier whether they have eggs or not.
Conditioning Your Betta Fish for Spawning
You may be tempted to add your female directly into the aquarium. If your aquarium is spacious enough (20+ gallons) and has lots of breaks in line of sight and places to hide then she should be fine. While male Betta Fish are less aggressive towards potential mates if she isn’t ready he will eventually start to bully and harass her. In a smaller tank this can lead to death if she has nowhere to flee.
One option for smaller tanks is to keep the female separate but visible. Placing her in a livebearer breeding trap or even setting a divider between each half of the tank will encourage them by sight and smell via hormones to prepare for mating without the male attacking her if she’s not ready.
You need to keep water conditions optimal and provide both heat and nutrient rich foods like Tubifex, Brine Shrimp, and Bloodworms. The warm, clean water and rich live and frozen foods combined with hormonal and behavioral triggers will stimulate the male to build a bubble nest (if he hasn’t already) and the female to begin egg production.
In nature male Bettas build their bubble nests in still water areas. If you can divert the flow of your filter or provide plenty of floating live or plastic plants to provide still areas of the surface then do so.
Once the bubble nest is complete the male will defend his still patch of water vigorously from intruders while attempting to entice the female to visit. Once her eggs have fully developed the female enters beneath the nest and the two mate by a twisting embrace called the Nuptial Dance.
The eggs are fertilized in the water column and picked up by the male afterwards. He then gently spits them into his bubble nest where they develop over the course of 36 to 72 hours, temperature depending.
Betta Fish Fry Care
Unlike most fish male Betta Fish take great care of their babies. They add new bubbles continually and aggressively defend that patch of the surface from possible predators. Once the fry hatch they find it hard to stick to the bubbles. However the father dutifully catches and sticks the young back into the next until they reach their free swimming phase in 3-4 days.
If you wish to raise the babies you’re better off netting the entire nest and moving the young to a fry rearing aquarium. Young Betta Fish are especially tiny and need infusoria (plankton), green water algae algae, and other microscopic prey items. Raising microorganisms as live food isn’t too difficult and I lay out the steps in my Live Fish Food article.
As they grow you’ll need to upgrade the food in size to items like Microworms, baby Brine Shrimp, powdered flake, Daphnia, and eventually adult offerings like small pellets and flake. Assuming you keep an eye on water quality, feed well and take good care of them your Betta Fish will reach adulthood over the course of four months!
Betta Fish Care: Troubleshooting
Bettas are some of the best first fish you could ask for but you may have problems arise. Here are some frequently asked questions that come up:
My Betta Tank is Growing Algae
Algae is an imbalance of light, nutrients, or both. If your Betta Fish tank or bowl gets a lot of natural light consider moving it to a different location or shading it somehow. An immediate 50% water change with a proper gravel siphoning will go a long way towards removing algae fertilizer. Follow up with a scrub brush if needed.
Overfeeding also leads to algae growth as the excess nutrients go right into the water column. In my Aquarium Algae Guide I break down the different types of algae and how to best treat them.
If you have space you may want to consider adding an algae eater. Small algae eaters like Otocinclus and Mollies work well in Betta Fish tanks! Here are some ideas on the Best Algae Eaters for your aquarium.
My Betta is Extremely Aggressive!
Sometimes you get a male Betta Fish that is hyper-aggressive. He chases all of its tank mates, nips at fins, and is a real terror. If you find he’s causing stress, moving him to an aquarium large enough for him to claim a secure territory can mitigate his wrath. Choose peaceful, fast moving fish that are too agile to be caught as tank mates, such as Danios, White Cloud Minnows, and small Tetras.
Betta Disease Symptoms
Make sure to look out for the following symptoms in your Betta fish:
Fuzzy patches on His Fins or Body
Fuzzy patches are fungal infections that have taken root. They are usually caused by an open wound exposed in poor quality water. A hefty water change followed by treatment with API’s Pimafix is what I recommend. It is a fantastic antifungal as are traditional chemical agents like Malachite Green. If you breed Bettas keeping an antifungal on hand is a good idea because fish eggs are sensitive to fungal infections.
Bloated Stomach with Scales Sticking Out
Dropsy is a complex, often fatal condition arising from internal bacterial infections causing fluid buildup in the body cavity. The Betta Fish’s body will bloat and the scales will stick straight out. Your best option is to move your Betta to a warm (80F) hospital tank and treat with both aquarium salt and antibacterial remedies like Melafix.
Grossly Enlarged Eyes
Popeye is an infection behind the eye caused by bacteria that proliferate in poor water conditions. Like Dropsy, antibiotics like Melafix xand aquarium salt in a hospital tank are the best cures!
Listless, Rarely Moves
Listlessness is a sign of high ammonia/nitrites/nitrates as well as low dissolved oxygen. Betta Fish can breathe air to mitigate low O2 levels but it can still affect them, especially when the other parameters are poor. Use water quality test strips to check your water conditions and treat accordingly.
Has your heater died? Colder temperatures also slow down Betta Fish.
White, Salt-like Specks Across the Body
Your Betta likely has ich, a parasitic disease that’s fortunately easily treated with any number of Freshwater Ich medications! Aquarium salt and warmer water also helps bolster the immune system!
Gasping, Brownish Gills
Gasping and gills that are brown rather than their normal red are a sign of high nitrates. Nitrates are the end product of the nitrogen cycle. In a healthy aquarium ammonia is converted into nitrite and then nitrate by beneficial bacteria.
Each transformation is less toxic to fish than the previous but nitrate is still poisonous if enough accumulates. The quickest way to deal with nitrate accumulation is to do a heavy water change.
My Betta Tank is Starting to Smell!
Smelly water is never a good sign! If you notice an unpleasant odor coming from your Betta Fish tank then a water change is definitely in order! You may be overfeeding, in which case the smell is rotting food. Or another fish may have died. Check for both as you prepare your siphon hose.
Bettas were some of my first fish because Betta Fish care is both easy and very rewarding. I have no doubt that if you’ve read this guide all the way through then you know everything necessary to keep your Betta Fish happy, healthy, and ready to spawn the next generation!
If there are any questions I missed feel free to ask them in the comments below!