fish tank for bettas

This is a simple and inexpensive way to make your own divider. which is perfect to put in your fish tank for bettas. The usual preference is over the net-like dividers that you can find in local pet stores.

I used this method to divide a standard 10 gallon tank in half so I could house a betta fish on each side. You can modify it for other tank sizes as well; though it is ideal for smaller sized tanks.


1. Plastic Canvas/Mesh

You can purchase the plastic canvas at most craft stores and some well known department stores. I purchased 2 sheets of ”Christmas Green” measuring 10.5″ x 13.5″.

Two sheets was what I used so I could have some extra stability. My betta fish had never been in a divided tank before so I decided to take extra precautions.

Darker colors also make it more difficult to see through as opposed to clear or lighter ones. It all depends on your animal’s personalities whether to take extra precautions.

2. Slide Lock Report Covers

The Report Holders/Slide Lock Report Covers have proven hard for some people to find. I recommend calling around to local office supply stores and department stores. I find mine at a CVS/pharmacy store.

They came in packs of 3 in black, white and blue. The cost was about 2 dollars (US) per pack. You will need at least 4, one for each side of your divider.

I purchased 2 packs and used the 2 blacks where they would be seen most (the sides) and other colors for the top/bottom.

You will not need the clear protective cover sheets for this project, only the slider binders.

3. Scissors

You will need these to cut out the dividers to match the dimension of your tank.

Follow the directions so that you don’t cut them too short.

Preparing your Fish Tank for Bettas

You will need a clear bottom to place your divider flush without any space or substrate in the way.

Doing this during a substrate change would be ideal or you can pile up the gravel, sand etc. if you don’t want to remove any.

This is very important as many animals including fish can dig to the other side if you leave a space under the substrate.

Also, make a removable measure mark on the outside of the tank so you can place your dividers evenly. I used a dry erase maker.


I started with cutting the plastic canvas the basic dimension of the tank. It will have to be smaller but it’s much easier to have to cut off a little more than to cut too much and start from scratch.

After you have the obvious excess cut off slide a report holder on each side. I had to trim the ends of the report holders to be placed on the top and bottom so they would fit together.

Once this is done you fitting it in the tank and removing it to make adjustments. It’s not the funnest part but most important.

Keep trimming off a little of the mesh at a time if necessary until it fits correctly. It should fit tightly and flush with no spaces on the bottom or sides, but with out the mesh bowing.

It’s important to remember it will fit differently with or without water and substrate. Often a perfectly snug divider can become loose on top or all over once you refill the water.

If you made your divider while the tank was partially full or empty with out realizing this you may need to make a new one or repair it.

An easy fix for this problem is to use one of the report holders and trim it a little less than the current one on the top. This will push the side holders apart and make for a tighter fit.

Tips for your Fish Tank for Bettas

  1. Make sure not to fill your tank to the top of the divider so your animals can not jump to each others’ sides, bettas are notorious for this.
  2. Using aquarium safe silicone to secure the divider is a great option for an extra secure and more permanent divider.
  3. The holes in the plastic canvas allow water to flow through but it’s still a good idea to have air stones. Place the stones in compartments that might not have as much surface agitation or are further away from the filter.
  4. It’s important to keep an eye on your animals and make sure they are getting along even with a divider. There are some bettas for example who just refuse to do well in a divided tank and will remain stressed at the presence of another betta.

Whether you make your own or purchase one, a tank divider is a great way to make room to expand your aquatic family so long as each animal is still given plenty of space.

You can even add some aquarium decorations that your bettas can enjoy.