I get a lot of questions of people about how to set up a tank for their wild bettas properly. Here is a proper guide on how to create a beautiful and awesome setup. If you have any questions, feel free to ask in the comments.
I always recommend people to get a tank between 15-40l. I house my adult bettas in tanks of ca. 15l each. Bettas don’t like big spaces and will get shy if you have a tank that is too big. If you do already have a tank that’s bigger, like 40l or 60l, I recommend just putting different structures like wood, plants, leaves in your tank so your bettas can hide.
Plants, plants, plants! Plants are one of the, if not the most important element of a good tank and lie on the base of a healthy and happy betta. Especially for wild bettas it is important to have live plants in your tank, as they make the water quality better, give a natural feel to the tank and are perfect hiding places. Around one third of the tank should be plants. Putting more plants in your tank will make your Betta hiding more.
The plants i use are coontail (Ceratophyllum demersum), Anubias, Java fern (Microsorum pteropus), Java moss and some floating plants like frogbit.
To prevent infections, diseases, to get your water parameters better and to give your water a natural look, I highly recommend catappa leaves. Catappa leaves are like the holy grail of medicines: they work both on prevention and treatment and they are 100% natural! Your fish will really colour up better with catappa leaves. As an alternative you can also use Alder plugs, banana leaves or Oak leaves. Wood also helps making your tank more beautiful, and it releases tannins too. Buy catappa leaves on Amazon.
A substrate is not necessarily needed, but it do makes your tank way more beautiful and often makes your bettas feel safer and colour up more nicely. As a substrate you can best use a kind of pH- lowering substrate. Here where I live, in Belgium, the pH is pretty high, so in most of my tanks I use a darker pH lowering bottom. Darker substrates let the colours of your Betta come out nicer, but it’s also your own preference. I mostly use ADA amazonia, it is quite expensive, but it is totally worth it if you want a high-quality bottom that goes for a long time in your tank. Buy ADA amazonia on Amazon