Betta Fish Tank Size

The biggest misconceptions regarding betta fish, are mostly about betta fish tank size. Fish stores keep them in tiny cups and love to tell people that they thrive in little glass bowls with no filter. The fact is, they might survive, but they most certainly will not thrive! You will often hear that they "live in puddles" in Thailand. This is not exactly true either. They live in rice paddies, which may be shallow, but they are spread out over an extremely large area, which means tons of water volume. That keeps the temperatures more stable and avoids any buildup of toxins, especially with all of the live plants. In the dry season, sometimes certain areas may dry up, and betta fish may find themselves trapped in a small puddle - however they will due whatever they can to move on to a bigger body of water, because they know a small puddle will surely end badly. The other thing to consider... is that betta splendens, the variety found in most fish stores, is not found in the wild at all. It is a domestic adaptation made over the years.

So... what is a good betta fish tank size? I recommend 2.5 gallons and up, and have had a lot of success and had some very happy bettas in 2.5 gallon tanks, though this is the smallest I would recommend, and you must also consider the shape of the tank as well. A tall column shaped 2.5 gallon tank will not have a sufficient amount of surface area, and will not be a good choice. With a 2.5 gallon tank, decorating the aquarium can be a challenge. Betta's love to have good hiding places, but you also must not "crowd" the tank too much either, which can be tough with the small footprint of a 2.5 gallon betta tank.

I find 5 gallon aquariums to be a great size for betta fish. They give you plenty of room to give the betta several good hiding places, plus leave some open room for swimming. It also gives you enough space to work with live plants - which bettas love. In addition, any aquarium under 5 gallons is very difficult to keep at a constant temperature. There are a few aquarium heaters made for smaller tanks, but in my experience they do not work all that well, plus they take up even more valuable space. Make sure the heater you get has a thermostat - many of the models for small aquariums are just "always on" which can lead to overheating quickly.

How big is too big? Most wild betta fish will try to dominate an area 3' x 3', with water up to 12" deep, which is over 67 gallons of volume. Keep in mind, these areas are heavily planted with lots of hiding places. The biggest thing to consider, is height - you don't really want a betta fish tank higher than 18" - 20" so they can get to the surface fairly easily. That means you could have a single (very happy) male betta fish in a heavily planted and decorated 55 gallon aquarium, and it wouldn't be a problem for the fish at all.

Whatever betta fish tank size you choose, remember to consider the weight of a filled aquarium. A single 5 gallon aquarium typically weighs around 62 pounds when filled. Below is a chart of the sizes and average filled weights of the standard aquariums most suitable for betta fish. There are also a lot of "specialty" aquariums, especially in the 2.5 - 10 gallon range. These often have unique shapes, such as a bowed or wavy front, though their filled weights should be similar to the ones listed below of the size water volume.


Another thing to remember - is that betta fish are jumpers! That means you need an aquarium with a secured cover or lid, otherwise you risk having your finned friend hop out onto the ground. With ample room to swin, and plenty of places to hide, your betta fish should be one very happy little guy!