Bettas and goldfish are two of the most popular fish species kept as pets, so it would be great to have both species swimming together in your home aquarium, right? But can bettas live with goldfish? Bettas are known for their aggressiveness towards other fish. So would your two pets fight and the betta fish eat the gold fish?
Read on to find out why keeping these two iconic species of fish together might not be the best course of action!
Betta fish and Goldfish
When it comes to choosing pets for kids, goldfish and bettas are at the top of the list. Without a doubt, they are both beautiful and hardy fish, but that is where the similarity between them ends.
Betta fish are members of the Osphronemidae family of tropical fish that hail from Southeast Asia. There are 73 varieties of betta fish, most of which are captive bred and heavily hybridized to create the spectacular fins and colors that fish keepers love.
There are wild populations of bettas, mainly in the Mekong and Chao Phraya river basins in Thailand, where the fish inhabit shallow, slow-moving water such as marshes, rice paddies, and floodplains. Bettas are labyrinth breathers, which means they have a specially developed respiratory organ that allows the fish to take deep breaths at the surface of the water.
That evolutionary quirk allows the fish to survive in oxygen-depleted water during the dry season. Unfortunately, that has led to the belief that betta fish can be kept in small vases or bowls without proper filtration, which is absolutely not the case. According to studies conducted by Adelphi University, bettas need a tank of at least two gallons with an efficient filter system, lighting and heating.
The goldfish you see for sale in pet stores around the world are descended from a species of wild Prussian carp that is native to Central Asia. There are thought to be around 125 species of goldfish, all of which have been produced through intensive hybridization and captive breeding. Unlike bettas, there are no officially recognized wild goldfish.
Like bettas, the wild carp from which modern goldfish are descended live in the slow-moving waters of lakes, ponds, ditches, and rivers. And, like many captive bettas, pet goldfish are often subjected to life in a bowl or small tank with no filtration system. That’s a disaster for goldfish as they are very dirty fish that produce a lot of waste so an efficient filter is essential.
betta fish aggression
Betta fish are also known as Siamese fighting fish and for good reason!
Male bettas are very territorial and will defend their patch to the death if necessary. About 700 years ago, the indigenous Thai people recognized that behavior and bred and bred wild bettas to fight. The owners of these «Plakats» and the spectators would bet on the outcome of the fights. In fact, in the 1800s, the King of Siam sanctioned betta fighting and owned fighting fish himself.
Goldfish, on the other hand, are pretty laid back creatures and also grow much larger than bettas. However, goldfish have a reputation for being fin-piercers, and your betta fish ‘s beautiful, flowing flapping of its wings would almost certainly be a prime target for your goldfish.
So, if you place a confirmed fin claw in the same environment as an aggressive, territorial fish that views any brightly colored creature with fins as a potential threat, you’re inviting carnage into your aquarium! See our recommended tank mates for betta fish here.
Cleaning and filtration
Goldfish are large, extremely dirty fish that produce enormous amounts of waste. That’s because a goldfish doesn’t have a stomach, so all the food it eats passes right through the fish and out into the tank. To control the pollution they create, your goldfish tank must have a mature biological filter system to manage the nitrogen cycle; otherwise, ammonia and nitrite levels in the water will quickly rise to toxic levels.
Unfortunately, while betta fish are pretty hardy critters, they are very sensitive to ammonia spikes and can easily succumb to ammonia poisoning, which often proves fatal.
Also, a tank containing goldfish requires frequent partial water changes to keep the water clean and hygienic. That’s fine for goldfish, but bettas get stressed by too-frequent water changes, which can compromise their immune systems and leave them susceptible to disease and parasite attack.
As mentioned above, a goldfish tank needs a pretty powerful filtration system to keep the tank water healthy for your fish. That means a pretty strong flow of water through the tank, and that won’t suit your betta at all. Bettas are very small fish compared to goldfish, and are not strong swimmers, preferring low to zero current. When he had a betta fish, his tank’s filter system had a baffle installed to restrict the current and keep it flowing. Alternatively, a gently bubbling sponge filter would work well in a betta tank.
In contrast, goldfish like to have a reasonably strong flow of water in their environment. Even my fantails enjoy playing with the bubbles and current that my filter system generates in their tank. Also, a sponge filter system will not be enough to deal with the amount of waste that goldfish produce.
Bettas are tropical fish that need warm water to thrive. The preferred temperature range for betta fish is between 75o and 86o Fahrenheit. If the tank temperature drops below 75o, your fish may experience temperature shock, or at the very least, its metabolism will slow down. When that happens, your fish will become listless, stop eating, and their compromised blood circulation can lead to diseases like fin rot.
Goldfish, on the other hand, are classified as cold water fish, living happily in water temperatures between 68o and 74o Fahrenheit. Goldfish can also experience temperature shock, but when the water is too hot, rather than too cold.
So you can see that goldfish and bettas are not at all compatible when it comes to their preferred water temperatures.
Goldfish grow considerably larger than bettas. So while a 10-gallon tank would be fine for a betta, it would be too small for a goldfish once the fish reaches maturity.
Tank décor is another area where goldfish and bettas have very different likes and dislikes. Betta fish prefer a densely planted aquarium with plenty of hiding and resting places. Goldfish prefer open water with plenty of room to swim. If you have fantails or fancy goldfish, they are very poor swimmers. Mine spend much of their time lurching around the tank, bumping into things or digging through the substrate, uprooting and destroying plants.
So too many plants, driftwood, and rocks may be perfect for a betta fish, but present a very real danger to goldfish.
Hardness of water
Fish extract the minerals they need from the water and have different tolerances for water hardness.
Bettas like soft water with little to no calcium (kH) content. The lower the calcium levels in the water, the lower the pH level, and betta fish need a pH of around 7.0 to thrive. However, goldfish prefer water that has a higher pH level in the range of 7.2 to 7.6, which has a higher calcium content.
Can you keep Bettas and Goldfish together temporarily?
In an emergency, for example, if your betta tank’s filtration system fails, you could theoretically put your betta in your goldfish tank for a day or so while you replace the filter unit. However, it would be best to temporarily house your betta in a quarantine tank if you have one.
So can your betta live with your pet goldfish? Unfortunately, there are many reasons why goldfish and bettas do not make suitable tankmates.
Bettas are tropical fish that live in warm waters, while goldfish are cold water fish. Bettas prefer soft water, while goldfish need water with a higher pH and more calcium content. Goldfish are very dirty fish that generate a high volume of waste that could cause an ammonia spike in the tank, which would be dangerous for your betta.
The Bottom Line: Although you could get away with putting a betta fish with a goldfish in an emergency, these two beauties are by no means compatible for long-term living together.
I hope you have enjoyed this article. If you have any questions, please enter them in the comment box below.