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5 Tips For Keeping A Betta Harem Aquarium!

The popularity of keeping betta fish just continues to grow at an exponential pace with there being so many viral photographs of beautiful looking betta fish going viral on social media encouraging people to get themselves a better fish.

Just like most things with fish keeping, once you start, it can be difficult to stop and people quickly end up owning multiple betta fish as well as trying their hands at betta sorority or betta harem tanks too.

Although a betta sorority is relatively easy to set up and keep for most fish keepers with at least a years worth of experience, a betta harem is a whole different type of tank.

Even experienced fish keepers can have a number of problems with keeping a suitable betta harem tank due to male betta fish being so unpredictable in the same tank, especially when female betta fish are involved.

Still, due to seeing so many questions about keeping a betta harem tank over the last six months or so, we have decided to publish this article offering some tips and tricks on how you can see your own betta harem tank up.

Implementing as many of these tips and tricks should increase the chances of your tank not having problems with aggression between the fish as well as ensuring that your male bettas will actually produce bubble nests and act naturally.

What Is A Betta Harem?

A betta harem tank is an aquarium that has been specifically designed to have multiple female betta fish with at least one betta fish male.

Some harem tanks will keep multiple betta fish males in it too if the tank is large enough but a single betta fish male will need around 20 gallons of territory in a betta harem tank so the number of males in the tank tend to depend on the size of your aquarium.

Think of a betta harem tank as a betta sorority that has at least one male betta fish added into the tank but some people will keep as many as three male betta fish in the tank.

It is usually not recommended that you keep more than three male betta fish in a betta harem tank as you usually need a sixty to eighty gallon tank for three male bettas in a single harem so costs quickly sky rocket.

Some people do also add other fish species into their betta harem tanks but this is usually not recommended, at least when doing the initial setup and the territories of your betta fish are being established.

Once this has occurred you can look to add other fish species into the tank such as ember tetras or algae eaters if you wish but many people will keep their betta harem tanks for betta fish and not add any other species.

Make Sure The Betta Harem Tank Is Large Enough!

The most common mistake that we see people make time and time again with betta fish is that their tank is simply too small for their fish.

You will usually need a tank of at least 40 gallons for a harem tank and this will usually only be suitable for a single male betta fish and as many as six female bettas.

This will ensure that you have plenty of space within the tank for the male betta to feel dominant while still offering territory for the female betta fish to stay out of each others way to keep aggression to a minimum.

You should always add as many fish hides and aquarium plants as possible to the tank to provide plenty of cover for the fish.

If you are wanting to have multiple male betta fish in a single harem tank then we would recommend a minimum of a 60 gallon aquarium for two male betta fish with up to eight female bettas.

An 80 gallon tank or more can usually hold three male betta fish and ten female bettas as well as offer enough space for various other fish species too.

Stock Your Betta Harem Tank Correctly!

Stocking your betta harem tank correctly can be a pain as the general rule of thumb of one inch of fish per gallon of water tends not to apply in a betta harem tank.

You have to factor in the aggression between the male betta fish and give them plenty of space to establish territory while also having smaller sections available for the female fish to try and develop their own territory too.

Our general rule is that you need a minimum of 40 gallons in a betta harem for a single male betta fish and then you add at least 20 gallons on top of that for each additional male betta fish you want to have in the tank.

When it comes to adding female betta fish, we usually recommend that you discount 10 gallons per male and 5 gallons per female betta fish but there are different stocking options available.

For example, if you have a 40 gallon tank you would use 10 gallons for the male betta leaving 30 gallons with the 30 remaining gallons divided by 5 gallons per female betta fish being 6 female bettas in the tank.

For a 60 gallon tank you would have the initial 40 gallons plus 20 gallons to allow for two male betta fish and then workout the total stocking.

This would be 60 gallons minus 10 gallons for each male leaving 40 gallons for females and 40 gallons divided by 5 gallons per female offers space for 8 female betta fish.

Make Sure A Betta Harem Tank Has Plenty Of Cover!

As we touched on earlier in the article, you really do need to offer plenty of cover in your betta harem tanks with fish hides and aquarium plants being the better options but any type of cover being great.

Some people try to ensure that there is enough cover to break up the available line of sight paths for the female bettas to see each other but this ends up taking a huge amount of real estate in the tank.

We usually just recommend that you fill out the tank with live plants and try to have 1.5 fish hide options per betta fish in the tank no matter if it is male or female.

This means for a 40 gallon betta harem with a single male and 6 females you will want around ten fish hide options if possible with plenty of plant coverage too.

Although there are a number of excellent, cheap fish hides on the market that you are able to use, you can get creative and come up with a range of different things.

There are also some great single feature, multi hides on the market now too. This means that one single fish hide has the ability to hide multiple fish in different areas of the hide with ease.

Ensure Your Betta Harem Has Plenty Of Food!

The three main issues that cause aggression in betta fish is territory, breeding rights, and food.

If you have followed our advice above then you should have plenty of territories available with breeding rights usually being sorted out via the natural hierarchy that developed in the tank. This leaves the food factor but thankfully, it is generally an easy one to manage with ease.

The majority of betta fish flakes are considered nutritionally complete for betta fish while also helping to maintain the color of the fish and prevent color fade too.

These can be an excellent primary food option for your bettas and ensure there is plenty of food available in the betta harem.

You are then able to supplement the food with treat options such as freeze-dried bloodworm or freeze-dried daphnia with both being excellent options.

Ensure that you try to add food to multiple areas of the tank to prevent aggression between the bettas in the tank, especially between the males who will establish their own territories and protect them.

Consider If Baby Betta Fish Are Actually A Good Idea!

Whenever you mix male and female betta fish, there is always a chance of there being baby betta fish produced and although the idea of your betta harem tank producing baby betta fish is nice, it is usually a bad thing to have happen.

Due to there being so much cover in the tank available, a surprisingly high amount of the betta fry may survive and grow into juvenile betta fish.

Many of these will be males and then you have the problem of having to find homes for your new baby betta fish or buy more tanks for yourself or displays of aggression will quickly start to break out. With a single male having access to so many females you can in theory produce twenty to one hundred juvenile betta fish too.

This is why we usually discourage people from trying to build out a betta harem and recommend people just stick to a betta sorority. Having a bunch of baby betta fish that you have to take care of pumps your costs up through the roof then the whole situation could have easily been avoided.


That brings our article going over our tips and tricks for keeping a betta harem tank. Although it can be an excellent experience to have under your belt as a fish keeper, the majority of people will be better of just going with a betta sorority tank rather than a betta haram tank. You are still able to mix and match a range of different betta fish options in a betta sorority without the risk of ending up with a huge number of un-expected baby betta fish.