The quick answer to “do betta fish need a filter?” is: It depends entirely on your betta’s aquarium setup and living environment. One of the troubles in giving a straight answer to this questions altogether is that, generally speaking, the betta fish enthusiast community is strictly on either one side of the fence, or the other. Many experienced betta fish owners are either adamant that yes, it’s absolutely necessary that you have a filter or no, it’s really not necessary at all.
What I’ve come to the conclusion of regarding why the betta fish community is so split is, generally people, as individuals, have a certain, exact, setup they stick to that works really well for them and, therefore, give all advice based on their “best setup”. So, it can get tricky when asking about whether or not betta fish need a filtered environment or not.
The bottom line is, you really have to look at your own, existing, betta aquarium setup and, after reading the information below, decide which is best for your betta and you. Lets go over some situations where you either should, or should not use a filter in your betta tank setup.
One of the most important things to take into account is that, if you do decide to use an aquarium filter, be mindful of the current it puts out. Betta fish stress easily and really don’t like to be constantly fighting a water current. This is especially true of the long tailed varieties. The longer fins and tails act as a sort of water anchor that get swept along with the current.
When it’s Betta to use a filter
If the betta fish aquarium is 2.5 gallons or larger, you should probably provide a filter.
If the betta fish aquarium is 2.5 gallons or larger, you should probably provide a filter. These larger betta tanks provide a nice amount of room for your betta fish to find places to escape any current put out by an aquarium filter.
It’s a good idea, in any case, that you look for an aquarium filter designed for use in an aquarium smaller than the one you have. An example of this would be, say, pairing a water filter rated for a 2 gallon aquarium in an aquarium that is 5 gallons.
Under sizing your betta’s aquarium filter in relation to the tank will make for a less turbulent environment. This allows for a more “stress free” place for your betta to live.
If your your betta fish is living with tank mates, your really need a filter. The additional waste products of the the betta’s tank buddies will cause an excess build up of aquarium pollution in no time. You will find yourself fighting off high nitrate and ammonia levels due to the breakdown of the extra fish waste, and this could spell disaster for your betta’s home sweet home.
Another reason to definitely setup an aquarium filter in this case is, and it sounds kind of silly really, the additional fish (and/or other aquatic creatures) living with your betta will use up the available oxygen in the aquarium more rapidly. That’s right. Your betta fish can run out of “air”. This is never a good thing.
Adding a filter to your betta’s aquarium aids in the oxygenation of the water while running. The filter will pull some of the air into the water it is filtering and then push the oxygenated, clean water into the tank. Again, you do want to think about getting a filter that is underrated for the tank size you are setting up.
When no filter is the Betta filter
If your betta is housed in an aquarium that is under 2.5 gallons, it’s actually not often a good idea
If your betta is housed in an aquarium that is under 2.5 gallons. It’s actually not often a good idea to setup an aquarium filter in these smaller sized tanks. What you do need however, is routine aquarium water changes.
It’s recommended that you have 100% of the aquarium water changed out every week. This is not ever to be done all at the same time! There are many ways you can set up your aquarium’s water changing routine. As a generalized example though, if you were to change out 20% of your betta’s tank water every-other day, this should suffice.
If the added water changes for these smaller sized tanks will absolutely not work into your schedule, there are aquarium filters made for these small tanks. Please be honest with yourself and do not substitute “I don’t want to” with “I really don’t have time to” when it comes to changing your tank’s water and the overall health and happiness of your betta fish.
If you have an aquarium set up in a situation where more than 20% of the tank’s volume consists of aquatic, live plants. This is a slightly more advanced setup, though it’s worth mentioning here.
The live aquatic plants in this situation will act as natural water filters for your betta’s aquarium. Nine out of ten times though, this setup will only work in an aquarium with only one fish, your betta fish. While live plants do work as natural filters, they work slowly and in smaller amounts compared to mechanical aquarium filters.
There is the added benefit of these live betta aquarium plants adding places for your betta fish to hide. Live aquatic plants also provide interactive stimulation to the betta fish.
There is however, a considerable amount of added tank maintenance needed for aquariums that have live aquatic plants. Not only that, but the more you have, the more routine maintenance is required. It does make for a very nice looking tank though if properly setup and maintained.
Betta make like a Sponge and Filter
One last thing regarding the use of filters in your betta’s aquarium, you might take a look at sponge filters. These filters work by an air pump pushing air through the sponge which creates a vacuum that pulls water through the sponge. There is hardly any turbulence caused to the aquarium, and little to no risk of your betta fish getting caught in the filter.
These filters are so gentle and safe that brine shrimp breeders use them. An example setup for these sponge filter’s in a 10 gallon tank would be a Jardin Fish Aquarium Mini Filter paired with a tetra whisper air pump and some PENN PLAX Standard Airline Tubing. When looking for this kind of setup in a different sized aquarium, the only thing you really need to change would be the air pump. The tubing and the sponge filter linked here should work fine in betta tanks up to 15 gallons. Any larger and you may think to add additional sponge filters.
Some people say this particular setup with the single filter works fine in 30 gallon aquariums. Just about every betta aquarium is different in some way. You really need to try something to see if it works for you. If not, add something or take something away!