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Can Guppies Live In Saltwater + Acclimatisation Guide!

The majority of fish keepers strictly think of the guppy as a freshwater fish but just like most other livebearers, guppies have evolved to live in areas of brackish water and they can be acclimated to live in fresh or saltwater.

With the recent viral videos on social media of a number of saltwater reef tanks containing guppies, we have noticed a spike in the number of people asking about acclimating a saltwater guppy.

Now, to be clear, a saltwater guppy is just a regular guppy that has been acclimated to live in a saltwater tank. They are not a different species of guppy but we have seen a few people getting a little confused and thinking that they need special guppies to live in saltwater.

Although you can buy pre-acclimated saltwater guppies online, they are usually overpriced for what you are actually getting for your money.

We have noticed a range of different questions being asked about keeping saltwater guppies and acclimating guppies to live in saltwater and we want to cover as many of them as possible in this article.

This is why we have added our table of contents to our article below so you are able to easily navigate to specific areas of the article quickly.

Can Guppies Live In Saltwater?

Guppies are salt-tolerant and the figure of being able to tolerate up to 150% of seawater salinity is commonly quoted but it is more of a spectrum that guppies are able to tolerate. A properly acclimated guppy can easily live in a saltwater tank without issue though.

In the wild guppies will swim through fresh, brackish, and saltwater at different times of their life.

Although most guppies can easily swim through fresh or brackish water without issue, they do usually need a period of time to get used to the saltwater before living in it for any length of time.

Please note that many commonly kept saltwater fish will see any guppies in their tank as a food source so you have to factor that in too.

It takes time and effort for you to acclimate your guppies to saltwater and it can be a waste of time if one of your other fish is just going to eat them.

Some people do try to breed guppies in saltwater as a food source for their marine fish but guppies tend to be too low on fat to provide a good food source.

Do Guppies Live In Freshwater Or Saltwater?

Guppies can live in both freshwater and saltwater with freshwater being the more common option for people who keep pet guppies.

It is generally recommended that once you have acclimated a guppy to saltwater, you keep the fish in a saltwater tank for the rest of its life if possible.

That said though, this is not essential, just generally recommended. A number of people who breed guppies will switch their guppies between fresh and saltwater at different times of the year, especially if it is a guppy with a rare pattern or colors.

This is usually done for the higher guppy fry yields and better survival rate in freshwater.

Due to this, some people who do have rarer looking guppies will acclimate their guppies to saltwater to live in their reef tanks as show fish for parts of the year and then switch them back to freshwater when it comes to breeding and repeat the process each year.

Do Guppies Live In The Ocean In The Wild?

Guppies are native to Antigua and Barbuda, Barbados, Suriname, Guyana, Trinidad and Tobago, and Venezuela and will usually live in bodies of freshwater but are commonly found in brackish water too.

In rare situations, guppies have been found in the ocean near freshwater sources but this tends to be due to a strong current pulling them out into the ocean.

Due to the proven ability for guppies to live in saltwater with minimal issues, it would not be out of the reason of possible to think that a number of guppies are living in the ocean in the wild.

If a guppy is pulled out of the fresh or brackish water than it would normally live in and into the ocean but it finds better food sources, it would stand to reason that the guppy would stay.

Although there are considerably more predators for guppies in saltwater than there are in freshwater, guppies could increase their survival rate due to large amounts of cover to hide from predators.

There are plenty of fish keepers who have their guppies in different types of saltwater tank with high survival rates proving that this can occur.

Can Guppies Live In Brackish Water?

Guppies can live in brackish water with it being a relatively common part of their life in the wild. Although the majority of the wild guppy population is located in bodies of freshwater, they are commonly seen in areas of brackish water in their native countries.

It is not actually known why guppies will traverse into brackish water so often but the dominant theory is that it is due to food shortages.

We have seen some theories that guppies will go into brackish or even saltwater in the wild to treat issues with bacteria or fungus but we have not seen any evidence to back this up.

Most areas of brackish water where wild guppies have been found tend to have a low flow rate to making sure that it is easy for the guppy to swim back to the saltwater.

As we touched on above, a stronger than usual tide in the areas of brackish water is probably the main reason that some wild guppies end up in the ocean.

How Long Does It Take To Acclimate Guppies To Saltwater?

It usually tasks around two weeks to convert a guppy to saltwater tolerance and fully acclimate the guppy to be able to live in a saltwater tank without issue.

Some guppies can take longer than this though and due to the acclimatization process being done in stages, you should delay moving on to the next stage if you notice any signs of distress in your guppy.

That said though, it is usually only weak, old or fish with a pre-existing condition that tend to struggle with the acclimatization process. The majority of healthy guppies will easily acclimatize to saltwater within two weeks.

We have seen some people report that younger guppies can acclimatize to saltwater in as little as a week too. Although fry yields from a breeding pair of guppies are usually lower in saltwater, guppy fry born into saltwater tend to acclimatize within hours.

6 Steps For Acclimating Guppies To Saltwater!

Here are our six steps to convert a guppy to saltwater as quickly as possible.

This is the general method that guppie keepers all over the world use to acclimate their guppies to saltwater and it will usually take around two weeks to complete the full process with a healthy guppy.

Get A Tank That Is Large Enough For The Process!

Although it may sound like common sense, we would not recommend that you try put your full guppy population through the acclimatization process on your first go and converting guppies to saltwater guppies.

Our minimum tank recommendation would be a a cheap 10 gallon tank that you are able to use for acclimating up to five guppies to saltwater at a time.

Add Your Initial Freshwater To The Tank!

We usually recommend that you fill your acclimatization tank to around 50%-75% of its maximum water volume.

If you are using a 10 gallon tank as recommended then you will be adding between five to seven and a half gallons of freshwater in the tank to ensure that there is plenty of space for the saltwater to be added to your guppy tank.

Attatch An Acclimatisation System

There are a number of acclimatisation systems that you are able to use but we recommend the Doradon FA18X Aquarium Acclimation System that retails at around $20.

Not only are you able to use it to add saltwater directly to your acclimatization tank but you are also able to use it to add water to bags of new guppies in the future too. The standard saltwater drip setting of one drop per second is usually fine for most health guppies.

Keep Your Saltwater Topped Up!

It is important that you keep your saltwater supply in your acclimation system topped up and don’t let it run out. Your guppies will require a steady and constant supply of saltwater being added to the tank to keep the survival rate as high as possible.

We usually recommend that you add fresh saltwater to your acclimatization system when you wake up and before you go to bed but adjust as required to your drip rate settings.

Start To Add Water Changes!

Once the acclimatization tank with your guppies in starts to get full, you simply remove parts of the brackish water in the tank to let the acclimation system top it up and increase the saltwater content.

The amount of brackish water to remove from the tank will depend on your drip rate but we usually recommend that you remove enough for two days of saltwater dripping at a time.

Add Your Acclimatized Saltwater Guppies To Your Saltwater Tank!

Although the guppies in your acclimatization tank will not be in 100% saltwater yet, the salt content in the water will be high enough and have been done gradually enough to fully acclimatize your guppies to saltwater.

You can not add them to your saltwater tank to let them enjoy their new aquarium.


That brings our article on the saltwater guppy to an end. We hope that we have been able to help you better understand the general process that you should be using to try and acclimatize your guppies to saltwater as quickly and safely as possible. There are a number of methods that you are able to do to convert our guppies from a freshwater fish to a saltwater fish though but we prefer our method above.