betta fish tank dividers

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What’s the major downside to keeping betta fish? In my opinion, it’s the fact that they must be kept separate due to their aggressive nature. To remedy this, you can opt for multiple betta tanks, or use tank dividers. 

Purpose of a Betta Tank Divider

As you become sucked into the betta fish hobby you will eventually want more than just one fish. I know it didn’t take me long before I wanted two, then three, and so on!

If this is you, you may have considered buying multiple tanks. One for each little betta. But with each betta fish needing at least 5 gallons this becomes impractical. The ideal solution to your newfound betta mania is purchasing one large betta tank and using dividers. This will create a separated fish tank with multiple habitats for each fish. 

There are a few different options if you choose to go this route. They are manufactured divided tanks, manufactured tank dividers, and Do It Yourself (DIY) tank dividers. 

Manufactured Divided Tanks

There are a couple of different store-bought options if you aren’t the DIY type. One of those options is a factory-made divided tank. Unfortunately there aren’t too many options if this is what you are looking for. 

Aqua One Betta Duo

For those of you looking for a new divided tank Aqua One offers a Duo and a Trio. You won’t need to worry about buying the correct sized dividers because they are pre-installed. These dividers are permanently fixed in place with silicone and are non-see through black. This is a plus because male bettas will become aggressive and stressed if they see other bettas.

The Duo is 5.3 gallons and the Trio is 8.4 gallons. This only leaves just over 2.5 gallons for each betta which is the absolute minimum amount of space for an adult betta. Ideally each betta should have at least 5 gallons. If this concerns you buy your own tank and go the DIY route.

This is one of the only divided fish tanks on the market that I’d recommend. Others designed for betta fish are just too small or have other issues. 

Tank Dividers

If you want a little more flexibility you can also install dividers yourself. These can either be store-bought or DIY tank dividers. These will give you more options in terms of tank selection, division sizes, and divider material. 

Manufactured Dividers

There are a variety of dividers on the market to choose from. These are a good option for those of you who want the flexibility of self-installed separators but don’t want to make them from scratch.

When choosing one of these make sure it is the correct size. One of the most common problems people have with these dividers is the proper fit. If they are too large they will not fit. If they are too small there will be gaps and your bettas will escape.

Dexter’s Dividers

I really like these Dexter’s Dividers. There are a variety of sizes to fit tanks from 5.5 to 90 gallons. These are made from durable solid black high-density polyethylene that your bettas will not be able to see through. I also like the fact that they have more holes than other similar dividers. This of course helps with the water flow between sections.

The only issue I have with these is the fact that they sometimes need alteration to fit properly. They are designed to fit a variety of tanks and because of this the fit isn’t always perfect. This means that you may need to carefully cut the edges down to get a proper fit. If you have some basic tools and rudimentary skills this shouldn’t be too much of a problem. 

DIY Tank Dividers

Not happy with store-bought options many people opt to build their own dividers. DIY dividers give you the most flexibility with your split fish tank. There are a wide variety of materials that can be used but the most common are plastic mesh, plexiglass, and PVC. 

Take a look at the video below for an example of a homemade divider. 

Things to consider with split fish tanks

While dividers are a great way to split your fish tank and separate your bettas there are some potential issues. 

Diseases in a multiple betta tank

Even though your bettas are separated they are still essentially in a community tank. If you are lazy and skip quarantining a new betta you run the risk of infecting all of your bettas. Common diseases like Ich are highly contagious and spread quickly. 

If one of your fish gets sick you will need to treat the whole tank.

Water Flow

Another consideration when dividing up a tank is water flow and filtration. Are your dividers water permeable? Will they allow water flow through them while still keeping each betta contained? Is each section receiving enough water flow and heat?

Depending upon your tank size and number of divisions you may be able to get by with one heater. With regards to filters however, I would recommend one sponge filter per section. These are great because they are small, operate submerged, run on an air pump, and create little water current. 

I would not recommend running a single, large, hang on back style power filter for split betta tanks. These will create too much current isolated in one section while not circulating enough clean water in others.

Security & Betta Jail Breaks

When you install your dividers it is important to make sure they are secure. The last thing you want is for a divider to come loose and allow your betta fish through. If this happens it is very likely that your little gems will kill one another.

This is the reason I am not crazy about using suction cups to hold dividers in place. As you may well know, suction cups are unreliable and often come loose. This is also the reason why you need to be careful with one size fits all manufactured dividers.

You also need to consider the possibility that your bettas may find their way over the divider. Betta fish all have an instinct to jump. This is how they are able to escape dwindling puddles of water during droughts in the wild. So, make sure there is a little gap as possible between your divider and tank lid. You may also want to consider keeping your water level lower if you do have a gap.

Tank Selection

When choosing a fish tank to be divided its best to find something that is long and shallow. Betta fish like to spend a lot of time near the surface of the water. A long shallow tank will maximize the amount of surface area they have access to. Tall tanks are not recommended due to the lack of surface area relative to the volume of water contained. 

Please also make sure each betta has a minimum of 2.5 gallons of water. I personally like to give bettas at least 5 gallons of space. So, if you are using a 10-gallon tank this means that you would have two sections and one divider. With a 20 gallon long aquarium you could have four sections with three dividers. 

Final Thoughts

I hope this has given you some insight, ideas, and motivation for your divided betta tank. The only thing better than one betta is two, or three, or maybe even four. Well, you get the point!