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Can Bettas Live In Brackish Water Or Not?

In the fresh water fish keeping world, the betta fish has gone from strength to strength over the last decade to grow to the second most commonly kept fish in the hobby second only to goldfish with the popularity of bettas still rapidly growing.

This is why the number of questions that we see from the betta keeping community just constantly increase and we have seen some people asking if bettas can live in brackish water or not so we wanted to publish an article on the topic.

There are multiple sub-species of betta fish with the betta splendens being the species that are commonly kept as pets and these bettas are not able to live in brackish water.

The betta mahachaiensis sub-species is a wild type of betta fish that is usually brown and can sometimes be found living in brackish water in the wild but their dull colors prevent them from being a commonly kept pet.

This is why there is so much confusion on social media about betta fish living in brackish water as people will talk about a betta mahachaiensis living in brackish water and other people will confuse it with the betta splenden species.

This has unfortunately resulted in some people accidentally putting their pet betta fish into brackish water resulting in a fatality so we would never recommend that you even try to keep your pet betta in anything other than suitable, fresh water.

Is It Possible To Acclimate Betta Fish To Brackish Water?

Although some people on social media do claim to have been able to acclimate their betta fish to brackish water, it is not recommended and there is minimal evidence that this can even be done.

There seems to be a sub-community within the betta keeping community who try to breed unique colors and be the first to do unique things with their betta fish and keeping one in brackish water seems to be a popular goal right now.

The bulk of these attempts just use a standard salt water acclimation system that we go over how to use in our article on acclimating guppies to saltwater with the general process being the exact same for betta fish.

The general idea is that you slowly transform the water that the betta fish is kept in to brackish water by slowly increasing the salinity levels of the water over a prolonged period of time but there is minimal evidence to show that this will even work with a betta splenden.

We have seen a number of other ideas on how you would theoretically be able to acclimate a betta fish to brackish water but we really would not recommend any of them for a betta splenden as they simply have not evolved to live in brackish water.

Simply keep your betta fish in standard fresh water and enjoy having your betta as a pet rather than trying to follow what is currently considered in trend on social media.

Can Bettas Live In Brackish Water Or Not?

The betta mahachaiensis sub-species of betta fish is able to survive in brackish water, at least for short periods of time without issue.

The betta splenden sub-species of betta fish that is commonly kept as pets due to their bright colors and unique fin and tail shapes are not able to live in brackish water and will often perish if they are placed in brackish water.

We know that there are betta fish available for sale on some websites that list them as being able to live in brackish water but these are the betta mahachaiensis sub-species that are not really kept as pets much.

This often results in some disappointed fish keepers when their betta mahachaiensis turns up as they tend to be all brown with pretty stand tails and fins with the sub-species being a harsh contrast to the betta splenden sub-species.

As we touched on earlier in the article, there are a number of people on social media who are either getting confused between the betta mahachaiensis and the betta splenden with their ability to live in brackish water or they are intentionally spreading misinformation.

This is why we never recommend that you pay much attention to anything that you see on social media unless you trust the source as taking advice from random accounts can often cause more harm than good.

What Will Happen To A Regular Betta Fish In Brackish Water?

A betta splenden, the type of betta commonly kept as a pet will usually perish if placed into brackish water, even for a short period of time.

This is due to freshwater fish like betta splendens not having evolved to live in hypertonic water sources meaning that their cells quickly start to shrivel up causing serious health problems in a short period of time that can quickly result in a fatality for the fish.

With the standard type of betta fish that are commonly kept as fish, this doesn’t matter if the salinity of their water is slowly increased over time or done all at once, the results will be the same.

Although the scientific cause behind it is totally different, try to imagine human drinking water having its salinity slowly increased over time, even small amounts will start to have an effect on us with serious problems quickly setting in.

This is the same for a betta splenden fish, they just have not evolved to be capable of surviving in brackish water or any type of water that has high salinity within its water.

There are various betta fish care guides available online that goe into great detail for the required water parameters of keeping a pet betta fish in your tank and they all tell you to use freshwater, not brackish water.


That brings our article going over if bettas can live in brackish water to an end and we hope that we have been able to stress that the standard betta splenden should never be put into brackish water. There is just no need to even try to keep a betta fish in higher salinity water or brackish water, just keep your betta in standard freshwater and your betta will be much better for it.