Are Betta Fish Freshwater Or Saltwater

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Betta fish have become extremely popular over the last decade, kept in home aquariums all over the world. A lingering question is whether betta fish are freshwater or saltwater (or even brackish) due to the harsh conditions they tolerate in the wild.

Betta fish are freshwater labyrinth fish, not saltwater. They prefer soft water with a degree of hardness (dH) less than 25. Betta fish also prefer neutral to slightly acidic aquarium water with a pH of 6.5 to 7. Some people think they live in saltwater because they can tolerate salt better than other fish.

Some people think betta fish live in saltwater because they live in rice paddies, ponds, and slow-moving streams in Thailand, Cambodia, Vietnam, and Laos, which may occasionally have some salt due to tidal flows or relentless monsoon rains that flood them for short periods.

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Labyrinth fish have a labyrinth organ, which enables them to breathe oxygen from the air, helping them survive in more difficult water conditions, as wild bettas would often need to do.

Another reason people ask if betta fish are freshwater or saltwater is that there’s a species of saltwater betta unrelated to freshwater betta fish, known as the “Marine betta” or “Comet.”

Make sure to check out our in-depth guide on betta splenden care.

Can You Put Betta Fish in Saltwater

Even though betta fish can tolerate higher levels of saltwater than many other freshwater aquarium fish, bettas should not be kept in saltwater tanks. Bettas can survive for a while in salt water, but bettas live and thrive in freshwater.

The betta’s natural home is the freshwater river basins of Thailand, where bettas evolved to live and breed. In nature, bettas avoid predators by living in heavily vegetated areas, which they rarely encounter in a saltwater tank.

Because betta fish can tolerate low salt levels, they can also survive in slightly brackish water, however too much or too little salt can upset how a fish regulates the level of solutes within their body. through the process of osmoregulation.

What Is Osmoregulation In Fish

Osmoregulation in fish involves several mechanisms, including ion uptake, excretion, and water balance regulation. Freshwater fish live in environments with lower concentrations of salt than their body fluids, so they actively uptake salts through specialized cells in their gills to maintain the proper salt balance.

Saltwater fish live in environments with higher salt concentrations than their body fluids, so they excrete excess salt through their gills and other organs to avoid dehydration.

Individual fish species are better at either increasing or decreasing the salinity level of their body fluids based on a water type specifically suited to them. Put your fish in the wrong type of water, and they will struggle to regulate their body fluids.

Osmoregulation is critical for the survival and health of fish and other aquatic organisms.

Can I Add Aquarium Salt To A Betta Tank

Many betta owners like to add aquarium salt to their betta tanks. Although unnecessary, this can be a positive step towards protecting against diseases such as betta white spot (Ich) and betta fin rot in low doses.

Aquarium salt can be bought at your local pet store and is a commonly used treatment against such illnesses. In small amounts, betta fish can tolerate salt just fine. Just be sure to research the correct dosage before adding salt to the betta tank.

betta tank salt
Aquarium salt can be added to your betta tank but use aquarium-safe salt with no chemical additives.

Salt does not evaporate like water, so you won’t need to add more salt when you top off the fish tank with fresh water.

I use API Aquarium Salt which can be purchased online. Find The Best Price For API Aquarium Salt

Betta Fish Water Requirements

Although I have mentioned that betta fish are quite a hardy fish species and can tolerate changes in water parameters outside of their usual range, it is important to note that bettas can “survive” these changes, not “thrive” in these changes. So what are the ideal betta fish water parameters?

You can find the ideal water parameters for betta fish in the table below.

ParameterSuggested Value
Prefered Water Hardness
dH (Degree of Hardness)
Soft (dH less than 25)
pH (Power of Hydrogen)Neutral to Slightly Acidic
(pH 6.5-7)
Preferred Water Temperature Range78° to 80° Fahrenheit, (25.5° – 26.7° Celsius)
Survivable Water Temperature Range72° – 86° Fahrenheit (22.2° – 30° Celsius)
Target Water Parameters For A Betta Tank

The parameters above are preferable for betta fish, so for community tanks, it’s best to find tank mates with similar needs.

Find out how to set up a betta tank correctly to avoid potential problems occurring afterward.

Tank Temperature

A common question that I hear is, “Do betta fish need a heater?” Betta fish are tropical fish requiring warm water, and when the betta tank water conditions remain within the ranges above, your betta will thrive. Betta fish will not mind too much if the parameters should fall outside of these ranges to a small degree.

Raising or lowering the temperature of the betta tank water by just a degree or two will be fine, providing this temperature remains stable. Betta fish are quite tolerant as long as the conditions they live in remain consistent.

Using a heater is the best way to keep your betta tank water temperature stable and at optimal conditions.


Betta fish prefer slow-moving water, similar to what they experience in their natural habitat, so you won’t need a strong filter system.

If your filter is too powerful, there are several ways to weaken the flow. You can point the filter toward the tank glass to diffuse it slightly, or raise the filter slightly above water level. Just ensure there is a strong enough flow to reach all areas of the tank.

betta tank filter
Filter are beneficial to your betta tank, but use an adjustable flow filter with a weaker flow rate.

If you don’t use a filtration system, and have a relatively small tank, you will need to change your betta fish tank water more frequently.


It is wise to add live plants to your betta tank where possible.

Plants create atmosphere and help emulate a wild betta fish’s natural environment. Live plants make a betta’s home more appealing and comfortable by adding natural beauty, providing a food source and somewhere to hide whilst also serving as an oxygenating plant.

Although you can buy a good selection of aquarium plants at your local pet store, you can also find an enormous selection online that are well packaged for shipping and arrive in excellent condition.

Check out the massive variety of aquarium plants available on Amazon


Keeping bettas can be very rewarding, and with a bit of knowledge, they are not difficult to look after.

As betta fish owners and betta keepers, we should ensure we understand betta fish water requirements, the correct tank temperature, and all other betta care basics before we take one home.

Frequently Asked Questions

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Jon O'Connell

I have kept both marine and freshwater fish and set up almost 100 aquariums. Although I am no longer doing it professionally, I hope I can help others to enjoy keeping happy, healthy fish by sharing my many years of experience.

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