Whether betta fish need a filter or not depends on several factors including tank size, the level of care, tank mates, and more. It’s not a simple yes or no answer because they can survive and even thrive in both scenarios with the right care.
Problems arise from misinformation and from beginner caretakers who believe a bowl or other small tank is going to be less work and less expensive. That’s simply not true and can lead to a sick betta or worse. Before you make your decision on filtration, make sure you fully read and understand the pros and cons of each.
Let’s start by understanding a betta’s natural habitat, living in rice paddies and shallow bodies of water. During droughts, a wild betta may even end up in a murky puddle for a period of time with very little oxygen. Betta fish are able to survive in these conditions through evolution, with the unique ability to gulp oxygen from the air (at the water’s surface) instead of relying solely on their gills. This ability comes from their labyrinth organ, classifying them as Anabantoidei or labyrinth fish.
Because of their level of tolerance in low oxygenated water, bettas are frequently sought after and recommended for beginners. They can be easier to care for than other tropical fish with less equipment, but myths are abundant. Claims how they prefer small habitats and can live off the roots of a plant in a vase. These claims are false and can lead to your betta merely surviving. Instead, you want your betta to live a long and healthy life without any suffering right?
Betta Fish Habitats Without Filters
Tanks that are 2.5 gallons or smaller, shouldn’t have a filter because they can do more harm than good. Filters in small tanks cause strong currents, which can toss a betta fish around and stress them out. Bettas are not very strong swimmers and their long fins can further complicate mobility in strong currents. Betta’s prefer slow moving or still water. This is why some caretakers swear by unfiltered tanks for their betta, replicating their natural ecosystem.
Water quality, however, quickly declines in low volume unfiltered tanks. The larger the volume, the slower the water quality will decline and the easier it is to maintain. Uneaten food and feces lead to ammonia, nitrate, and nitrites building up. In high quantities, these can begin to stress and make your betta sick. One of the most common ailments in small unfiltered tanks is fin and tail rot. There are also beneficial bacteria that naturally exist in the water. Constant water changes can limit these beneficial microorganisms and create stress as well.
The absolute minimum size for a betta fish is 2.5 gallons, with the recommended size being 5 gallons or more. Caring for a betta fish without a filter is actually a lot more work. Non-filtered tanks require 1-2 water cycles at around 25% and a full 100% water change each week (depending on water quality). On the other hand, a 5-gallon unfiltered tank will only need 1 water cycle per week at around 25%-35% of total volume and a 100% water change once per month.
You should also use test strips to analyze your water parameters in real-time. To help with unfiltered tanks, remove uneaten food and poop before it settles and decays (pro tip: use an aquarium designated turkey baster to easily suck debris out of the tank). After reading the section below, you’ll quickly realize why filtered tanks can be more beneficial for betta fish and easier to maintain.
Betta Fish Habitats With Filtered Tanks
There are many filters you can buy if your tank did not come with one. Some examples of different types include: under gravel filters, hanging on the back power filters, sponge filters, and internal filters. The most important consideration for betta fish is their strength, with having an adjustable flow being crucial. Your betta should be able to swim freely without struggling.
We recommend purchasing a tank that’s recommended for betta fish and comes with a filtration unit out of the box. Mix-matching items can be tricky, but if you are buying a filter, a weaker than the recommended size is advisable. For example, if your tank is 5 gallons, consider a filter rated for 1-3 gallons.
Benefits of Betta Tanks with Filters
- Waste Reduction – removal of excess food, feces, ammonia, and bad bacteria
- Oxygenation – filters help to oxygenate the water
- Good Bacteria – beneficial microorganisms accumulate in filter media and tanks
- Tank Mates – filters are required with tank mates because of increased bio loads
- Maintenance – reduced maintenance and water cycling
Betta fish like filtered tanks because they do best in stable water parameters. A filter helps to maintain beneficial bacteria while cleaning and neutralizing ammonia and nitrates. Establishing a natural ecosystem is crucial to long-term health and limiting the chances of stress and disease.
Filtered betta tanks will require less maintenance, which makes your life easier. If you forget to perform water changes in an unfiltered tank, things can get bad quickly. In a filtered tank you don’t need to do 100% water changes unless you have an algae or rampant disease problem. In fact, a 25-30% water cycle once a week and vacuuming the gravel is all that’s necessary aside from filter media replacement per your filter’s instructions. Make sure to always clean your filter in tank water and not tap water to preserve beneficial bacteria.
Is Your Bettas Filter Too Strong?
If your betta’s filter is too strong you will need to remove it or reduce the strength of the current. Filters are not ideal for tanks under 3 gallons and you should upgrade the size of your betta’s habitat. Hanging on the back and internal filters come in varying strengths and may be too strong for a betta fish. If your betta is struggling to get to the surface for air, hiding and scared, and frantically swimming in the current, your filter is probably too strong.
This can severely stress your betta fish and lead to fin damage, injuries, and even death. After becoming physically exhausted they can be tossed around or even sucked up by the filters intake tube. Allowing your tank’s water to get and stay below the recommended depth from the filter’s output will also increase turbulence in the water.
The first thing to try is limiting the flow of your filter if it’s adjustable (try the lowest setting). If not, consider returning it, purchasing a new one, or trying these tips. You can increase plants and decorations near the filter to break the flow as it enters the tank. There are also other methods like creating a separate compartment for filtration by dividing the tank.
Another quick fix which will also protect your betta fish is placing a pre-filter sponge on the intake tube to restrict water uptake and ultimately output. Pre-filter sponges will easily fit over certain filters’ output tubes into the aquarium like the Fluval Spec V too. This can help to reduce the flow and turbulence in the tank for betta fish.
Recommended Betta Filters
The size of your tank or habitat will affect which filter is right for your betta. One of the best and most inexpensive options for smaller tanks are sponge filters (on the left). Sponge filters use bubbles of air from an air pump to draw water through a sponge. A sponge filter is very easy to set up and allows for both mechanical and biological filtration. They are perfect for the delicate betta, and also have the added benefit of oxygenation. They work best in tanks up to 10 gallons and present virtually no risk to your betta from suction or flow.
A second option is the hanging on the back (HOB) nano filter (middle). These are ideal for 5-10 gallon or even larger tanks. If you can, get one that has an adjustable flow rate and consider a pre-filter sponge for the intake tube. HOB filters are easy to maintain and they don’t take up viewing or ecosystem space.
A final option is an internal filtration unit that goes inside the tank (on the right). If you already have a small tank (3 gallons), this can reduce swimming space and the overall water volume available for your betta fish. Most submersible filters attach to the tank’s wall via suction cups and perform relatively well if they’re not too powerful.
Conclusion
Do betta fish need a filter? That depends on what you’ve decided given the pros and cons for each scenario above and your personal situation and preference. Please avoid fish bowls and any tank under 2.5 gallons. The larger your tank, the easier it will be to maintain. A filtered tank can further support a healthy ecosystem too. If you decide to introduce tank mates, create a sorority, or place your betta fish in a community tank, filtration will be required for increased oxygenation and water quality.
If you still have questions, please ask them in the comments below.
After a dismal and frustrating experience with some carnival goldfish, I’m researching so I and any fish I get have a better experience. I’m considering a Betta.
I have a fishless 12 gallon tank with an internal filter (it takes in water from the bottom and sort of pours in back in from the top). I’d like to reuse the set up with the addition of a heater. According to test strips the water was good though perhaps a a bit soft and alkalinity slightly lower than ideal.
If the filter is to strong would a structural barrier help reduce the flow?
Is 12 gallon too big for a betta?
Any other cautions?
Any help would be appreciated.
Sorry about the previous goldfish experience, but I’m sure you will quickly love keeping a betta. A 12 gallon isn’t too big for a betta, you’ll just need to make sure the tank has a lot of plants/decor and places to rest/hide to replicate a betta’s habitat and for them to feel safe and not stressed. Using your current filter could definitely be an option. If it’s not an adjustable flow, then you can have it close to a wall or break onto a structure. Just monitor and make sure it’s not keeping your betta swimming constantly, or leading to fin damage. Definitely get a heater that has an internal thermostat too, you’ll thank me later.
Hello Bryan. I am going to buy my fourth Betta later this week (The others, unfortunately, are no longer alive, due to age, disease, and malfunctioning heaters, all but the last when I was very young.) and already have the tank and decorations set up. It is a 5.5-gallon tank with filter and live plants. I have an air pump filter, but have realized that it will likely be far too strong for a Betta. I have the smallest air pump my pet store had. I have one idea (Some type of clamp on the tubing) but was wondering if you knew of any better ideas or if there was something specific to use.
I also was wondering about heaters, because I am rather nervous about using one after my last Betta died when it overheated the water to 90 Fahrenheit. There is some fluctuation in the area where the tank is (70-76) and am uncertain if it’s worth the risk.
I do not actually have the Betta yet, because of afore-mentioned problems I have had in the past. I greatly want to make this work.
If by air-pump filter you mean a sponge filter setup then you should be fine. Hanging on the back filters are generally the ones which are too strong for a betta unless adjustable. For heaters, make sure you get a high quality brand (i.e. Aqueon) with a built in thermostat that will shut off once it reaches 78 degrees and turns back on when it dips below. These are the safest in my opinion. You’ll want to maintain a tropical habitat for your betta to keep his immune system and activity level proper.
I have a hang on the back filter but I have to keep the water flow to its minimal setting because I don’t want my betta to be tossed around. However, this is causing my tank to be under-filtered. I want to get a hang on the back filter but I am confused on what exactly I should get and what products I should use and how to set it up. Do you have a list of all the products I need to set it up? That would really help Thanks.
Hey isaac;
In my ten gallon community tank I’ve found that it’s possible to keep the filtration high if you raise the water level. This reduces the current while keeping the tank filtered. Don’t forget to include hiding spots that inside break up the current and allow it to be relatively still to allow them to have areas they can rest. Hope this helps 🙂
I have my Betta in a 3g unfiltered tank. I do 100% water changes once a week, that’s it. Can I leave him in this size tank indefinitely? Do I need a filter since it is technically bigger then 2.5g?
Sure you can, and filtration is up to you, as long as you stay up on proper maintenance a filter isn’t ‘required’
Hi! I just got a betta 3 days ago and I want to get a filter. I have a 5.5 gallon tank and was considering a sponge filter because they’re quiet and relatively small. There’s so many different kinds, some have tubes and pumps and some don’t, that I’m not sure which one I can get? I’m at a loss haha
Setting up a 3-gallon tank now for a un-acquired Betta fish. New at this.
Hi there. Great article on Betta tank filters!
I have 2 bettas kept in separate identical unfiltered tanks. They are not big. 7L each. Currently changing 50% of water every week.
I am thinking of getting small HOB filters with adjustable power for each tank, switching on the filters for only a couple of hours at night just to filter of dirty stuff accumulated in them. Of course the weekly water changes will continue.
Not sure if this setup will be better for the bettas?
It would be better if the tanks were larger, however, I would recommend a sponge filter with aeration for that size tank and not the HOB filter because it will likely be too strong and cause more problems in a small habitat.
So, a 2.5 gallon should not have a filter? or is a sponge filter ok?
Sponge filters are okay for that size.
I have a betta in a 3 gal bowl, no filter with a moss ball and another live plant, so is it ok not to do 100% water changes? I have been doing 25% changes twice per week. The water is more murky, but he seems happier.
If you’re doing 2x weekly water changes at 25% you may only need to do 100% changes when deeper cleanings are needed (e.g. stress indicators, cleaning substrate, tank, ornaments, plants, algae-build up, or any water parameter or ammonia spikes).
Hello,
I am upgrading from a 1/2 gal bowl with a few golden pothos roots weighed down by a few river rocks, to a 3. gal glass tank, will the plants be enough to filter the water with perhaps bi monthly water changes? The bowl is staying clean as of now, just change water 1 x a month.
Thank you for any info.
That’s too long to go without water changes. The plants won’t be enough and I would recommend a 25% change weekly and maybe full water changes monthly. Maybe sooner depending on how well you keep things clean in between and you can use some test strips to monitor ammonia levels.
Hi! Great post. I tried to set up a sponge filter in a five gallon tank for my new little Betta but I am not going to be able to take the noise of the air pump running all the time next to me (which is where he’s happiest ). So here’s my question: if I make it a bare-bottom tank, which I assume would be easier to clean regularly, (with plants and hiding places of course) and no filter – what would be the best procedure to maintain a healthy tank and Betta? I am currently changing his 2 gallon bowl every three days. I would prefer to do so less often of course. Once a week would be doable for me. And do I need to do a full water change since there is no filter? So much conflicting advice I appreciate any input. If you have a recommendation for a quiet filter I would also love to hear that! Thank you 🙂 oh and I have moss balls in his bowl and can get more when o switch him to his tank. Do those help?
Marimo moss balls will definitely help to remove and process some waste. In a 2-gallon tank, you can go without a filter and no substrate and just use a turkey baster to suck up any poop or excess food in between full tank cleanings. Also, doing 20-30% water changes a couple times a week will drastically improve your water quality too in between the weekly change.
I forgot I have one more question: Would a sponge filter still be effective if I just turn the filter on overnight and turn it off during the day.?
Yes, just not as effective as running it all the time.
Hello! So I’m a beginner wannabe betta owner. I have a few questions. I want to get the deep blue professional 2.5 fish tank. I’m interested in getting a sponge filter and an some type of light. What sponge filter and light would work well with a betta fish? Also would I stil need an air filter if I get a sponge one?
Why not consider a setup that comes ready to go out of the box like the Fluval Spec III 2.6 gallon tank? It has a light and filter that comes with it. You will likely be happier in the long-run than trying to piece together items.
We just got our first betta fish. We got a 2-gallon tank because it was in our price range, with some lovely plants and hiding places. Our betta seems to have her favorite places and alternates between resting in them and swimming around. Our tank came with an internal filter that sits at the top of the tank. Because our tank is 2 gallons, it sounds like you don’t recommend the filter, but the tank is vertical, and she is quite active and doesn’t seem to have any trouble with the current. It appears to be a very mild current. However that being said, when we try to feed her, the food that would normally sit at the surface for her to eat gets swirled around in the current and broken up rapidly, which then causes it to sink to the bottom of the tank. First of all… can Betta’s smell food and find it near the bottom of the tank, or do they only surface-eat? Secondly, would you recommend turning off the filter every time we feed her so it doesn’t break up the food, or turning off the filter for good? I would really like to keep it on because I want her tank to not get grimy as fast… thanks for your input!
Hi Laura. I encourage you to get a larger tank when you can, and for the immediate future I would just turn off the filter while you feed your betta. They gobble up their food so quickly that it won’t be off for very long. Betta fish can detect ‘smell’ food, yes, but are typically surface feeders. All are different, but some won’t eat food from the bottom. If your betta does not mind the mild current, and it’s not stressing him or her, then you should be ok.
Hi! Your site has been a wealth of information. Thank-you! I’m a new Betta/fish owner and am wondering how to clean a carbon filter and how often I should change it? Also, when doing small water changes can you over do it on water conditioner? I only put in a few drops in new water when I do a 10-15% water change weekly. I have a 5gal tank, heater, filter, live plants etc. Lola seems pretty happy about the set up.
Cheers!
Thanks, Kim! I would recommend reading the instructions on the specific carbon filter you have and how often it should be replaced. Can you overdo it on water conditioner, yes, but it would likely take a lot more than a few extra drops. What I do is keep a 1-gallon jug with conditioned water in it and that way I don’t need to estimate the drops.
What is condintioned water?
Conditioned water is water that has been treated with a water conditioner to remove harmful things like Chlorine. Like this one from API.
I have a 1.5 gal wall mounted tank for my betta. Was going to shop for a small plant that will grow out of tank and help reduce his waste and filter water for him absorbing his waste. Also thinking about a few small moss balls
Hello, I have a 1.5 gallon tank. I am wondering if this is too small, and what would be the best way to clean the tank. Would live plants be better? Do I need a thermometer?
Live plants, like marimo moss balls, can help clean the tank and oxygenate the water. I do recommend you get a larger tank when you can though. If you mean a 100% water change cleaning, never use soap. Just rinse everything under hot, hot tap water and scrub off any algae or build up as necessary. Thermometers help to read the temperature of tank’s water, if it’s below 78 degrees Fahrenheit, then you should get a heater as well to maintain proper tropical temperatures.
Hi Bryan. So great to find someone with all the answers. I actually have 2 bettas each in 1 gallon tank. I had no idea that is too small. Store clerk said its fine for Betta. They have a filter that I rinse every 2 weeks when I change water. I did not know that I have to rinse it in the tank so I did it under the running water. Have a done much damage? When I bought the fish I was told to do that and that I have to change filter every 3 months. So now I read that I should not do that because that bacteria is actually good for them, right? The fish seem fine and there is not much movement of the water on top. The only thing that happened now is that one tank started to grow green algae on the walls of the tank. Is that bad and what do I need to do? Thank you. Bryan
Hi Polona, yes, unfortunately, a lot of pet store employees are misinformed. Regarding the filter, there are bad and good bacteria that can be present. Rinsing the filter in the tank’s water does help to retain some beneficial bacteria in the filter media, which is why that’s recommended. Changing the filter every 3 months is okay, and necessary. The green algae may be growing if you have the tank exposed to sunlight (e.g. near a window). Just use a small aquarium brush to brush it off so it doesn’t continue to grow and do more frequent water changes.
Walmart done tricked me, I bought a betta viewer, not a tank! The viewer is half a gallon….see I got so happy that I paid this no mind for my son, but there is a big difference between viewers and a tank am I right. With that being said he’s always at the top seeming not to get enough air. He moves at a minimum only to eat, then back to the corner… is he sick? I have an idea of what to do after reading your article, but I must know for sure?
Yes, Michelle, those tiny tanks are for placing your fish in to view them up close, or during tank cleanings, they are not permanent housing. While betta fish do dwell near the surface of a tank, he may be staying towards the top and being lethargic in the corner because the water in that small viewer quickly gets dirty and ammonia builds up and can cause stress, labored breathing, fin rot and lots more. Please get a larger habitat as soon as you can.
I bought my daughter a 10-gallon tank, which included a filter, fake plants, decoration and gravel for Goldie Bob (the goldfish she won). Sadly Goldie Bob died. I love Bettas but have never had them in a tank that large, nor with a filter. Would a beta thrive in her tank or should I just get her another goldfish?
A betta would be great in that size tank, and you could even consider some suitable tankmates too at that capacity habitat.
Hi Bryan,
I read the article and I’ll read more in your blog due to I think it’s very clear especially for beginners as me.
I used to have 3 goldies that I deeply love, unfortunately just for four months, they died for cotton fungus. After a while, I decided to try again.
I read few things about bettas, unfortunately not enough to let me set a new tank right now.
I got few questions if you can answer. I got a 54L tank around 14 U.S. gallons, do you think a betta will be fine on it? What filter will you recommend? I thought about a sponge filter with few anubias in the tank, but I need a new silent, hopefully, low-cost air pump to let it work and I don’t really know what to get. I’m also afraid that I bleached too much my tank, do you think with lots of water changes and salt and vinegar I can fix it and reuse it? Maybe I didn’t but as beginners don’t really know. I also need to know if I can use API stress coat as de-chlorine.
Last question ( sorry) do you use for betta product to detox ammonia, nitrates and nitrite as kordon amquel plus? I’m very sorry for all these questions but I’m trying to learn as much as I can before to get any other fish. I’m still heartbroken, I don’t want another dead friend. Thank you.
Thanks, Stefi – the 14-gallon will be okay as long as it’s got some hiding places and plants as you said you’re going to add. I would recommend an adjustable flow filter (like this one) so you can slow it down for a betta. If you used bleach, you can still use the tank, just make sure to rinse it very, very thoroughly and then let it sit out and dry completely for 2-3 days before refilling it. Yes, API Stresscoat makes tap water safe and removes chlorine. And for your last question, the filter and water changes should help with that, I wouldn’t use a product to remove ammonia.
If I am doing a 10 gallon tank with one Betta do I need a filter?
I would. Filter media houses beneficial bacteria and helps remove toxins that can stress or harm your betta. It makes maintenance easier and also helps to aerate the tank’s water. Just make sure the flow isn’t too fast for a betta – an adjustable flow filter is usually best.
Hello, I bought a 3-gallon Marineland aquarium with led lights for my betta fish. It comes with a filter and air pump. I added a heater that keeps temps at 78 and a few plants. My problem is the filter even when set at its lowest setting, and making sure I keep it below the water level is still quite strong! I had to add a tall tropical live fern to break some current but wondering what else I could do that is minimal. I chose this tank for its ease of use but I’m concerned the filter is too strong. Appreciate the help.
Well, you have a few options. Add more plants or decor near the filter, buy a different filter that’s more adjustable, use a sponge-style filter with the air pump (best option), or go filterless and just do more frequent water changes.
Hello Bryan,
I’m a true novice. I did put a fern but want my betta to have enough space to swim. He does not seem so stress but still. I wanted to ask you for this particular aquarium would you have a link to what a sponge-style filter with the air pump looks like? Also I bought a water test kit and find ti so confusing. Could you tell me if it is really necessary to measure PH nitrate nitrite etc ? I bought a turkey baster type to supposedly remove excess debris and I must say it does not work it removes lots of water if I were to try to remove small debris I see. My bottom is more like sand like than pebbles. I’m concerned I cannot clean the debris with that tool I got 🙁 What would you suggest I do about these issues. Really appreciate your help. Nathalie
Okay, that makes sense. Do a Google search for “sponge filter aquarium setup” and you can then view the images. Yes, it’s necessary to monitor pH, ammonia, nitrites, and nitrates. pH should be 6.5-7.5, ammonia should always ideally be 0ppm, nitrates should be around 10-20, and nitrites should be 0. As for the substrate, you may have to switch to pebbles if it’s easier for you to clean. The sand-like substrate will inevitably get sucked up during cleanings and need to be replaced over time.
Hello. I bought a 5 gallon tank for two females I am expecting this week (they are being shipped). I have always owned smaller tanks and did not realize I have to cycle my tank before hand. Do you think it would be okay to keep the fish in 1 gallon jars until the cycle is ready? And just keep a close eye on the water and do frequent water changes?
Yeah, you could do that, or use a quick start product to introduce beneficial bacteria without cycling. It’s not as effective, but would be better than the 1-gallon jars. Do you have a divider? I do not recommend housing 2 females together as they will likely fight and stress each other out until one eventually dies.
Hi, we really need some help with our beta fish. He was a very active fish a few months ago but suddenly stopped swimming and prefers to lie at the bottom of the tank. It’s been a couple months now and he is still very immobile, to the level that he only swims now to come to the top when we provide food to him. We have tried everything from checking the water quality using strips to adding conditioner, beta fin fix medicine and recently when we saw white spots around his gills we tried an anti-fungus treatment. We are really worried for our fish and would love to hear from you if you can suggest us and provide any help. Can we take him to any vet? We are in New Jersey and if we can visit a vet what type of vet should I be looking for on the internet. Please help.
What size habitat? Is the tank heated and filtered? Are the strips showing the water quality is okay? How old is he? Most vets don’t specialize in fish, so I’m not sure I can help you there, but I think with a little care we can get him back on track. If he has a fungus, I would try something better than Bettafix, like API Fungus Cure. Also, it wouldn’t hurt to be doing daily water changes of 20% to keep the water clean, clean.
He is in a fish bowl. The water is neither filtered nor heated. The strips show everything in control except once they showed a color trending towards water being hard and once trending towards 0.5 chlorine but it now shows all neutral. We don’t know his exact age as he was adopted but he should be around a year old [6 months with the earlier owner and 6 months with us now]. Should we buy a new tank with a filter? Now he is lying on his side all day at the bottom of the tank and his gills seem to show labored breathing. Please let us know your thoughts that can help him in any way, we are out of options 🙁
That habitat is not conducive to proper betta health. Please read the betta care page in its entirety and yes, you should have a habitat that is at a minimum 2.5-gallons with a heater, and filters are not required but do help a lot for beneficial bacteria. His symptoms are likely from too cold of water, and ammonia and other things building up quickly in a bowl.
Hi
I am new to taking care of Betta fish. I have him in a 10 gallon tank and use the
Marina s10 filter which is keeping the water beautifully clear.
My question is, what may I use as an alternative to the slim filters because they can be quite costly? There is so much information out there on different media, sponges etc. it has my head spinning.
Great site!!
Thank you!
Susan
Cartridges can get expensive, but it’s a good thing food for fish is really cheap! There are DIY options specifically for your filter, and for HOB filters in general. You can usually use them well past what the box says instruction-wise too, with just some good rinsing and cleaning in tank water from time to time.
I have had my Betta fish “Benny” for 2 months now and just love him. I have him n a 5-Gallon Tetra tank with filter and all the trimmings to go with it. So far he is doing well and almost eats his 3 pellets twice a day almost out of my finger. We have been changing the filter, cleaning and at least half of the water every 30 days but this last time it was 34 days and I noticed that the water started turning green and the filter was full of algae and some of the artificial plants were slimed over. We used the special cleaner to suck up the debris from the gravel and changed half the water, and filter and wiped down the tank. Also, we buy spring water instead of tap. Also, put in the safe start and easy balance plus. After 2 days the water seems to be almost clear again. Did we do enough and will the algae come back? should we have totally cleared it out? sorry for the long story, but I am new at this.
You did enough, algae can build up and is easily scraped off with an aquarium cleaning brush or sponge. It may come back if you wait too long during water changes like that (increase the frequency), or if the tank is exposed to too much light.
Hello,
Moonlight seems happy in her 3 gallons tank with only live plants. Was able to control the current issue and I do testing on her water. I give her a pea each week and hopefully this helps. What I wanted to know is it’s time to do a full water change. I have had her for a month. Do I rinse all live plants before putting them in the new conditioned water? Thank you for all the help!
Great to hear Nathalie. 100% water changes only need to be done when the tank is especially dirty. If that’s the case, then yes, rinse all filter media in tank water (not tap water) to preserve healthy bacteria, and yes the live plants can be rinsed prior to re-entry. And remember to acclimate your betta back into the tank’s new water to prevent shock.
Bryan, Thank you so much for your incredible help. I’ll test her water today and see how it is it does, it does not look cloudy. In case I need to change water today, what. do you mean by making sure Moonlight gets acclimated to new water? How would I do that?? Really appreciate you teaching all of us. Warmly, Nathalie
It’s the process you should have followed when you first introduced your betta to its new home. Floating the cup or bag in the water to acclimate the betta to the water temperature in the tank slowly, and slowly introducing small amounts of the tank’s water into the bag during the acclimation period. You can read more about the process here.
So when we do a partial cleaning of the tank we take out our fish ? OR just add the fresh water to the bowl
Only remove the betta fish during 100% water changes, not during partial changes.
Hello!
I just bought a Betta and put him in the Tetra Half Moon Starter Kit tank (3 gal). The lights are attached to the filter/bubbler so I can’t turn them off at night unless I turn everything off. Do you recommend I turn everything off at night to give him rest or should I keep everything on 24/7?
Thanks!
Well, that’s quite frustrating huh? I would recommend shutting everything off at night then.
Hi, the guy at Petsmart recommended the Tetra Whisper for my Dragon Scale Betta, so that’s what I ended up getting. My fish HATES this filter, he won’t swim near it and freaks out if he gets caught in the output water because it moves him around, and I really don’t want him to be stressed. It’s a smaller tank than I would like because I’m living in a college dorm right now. I was considering getting rid of the filter and replacing it with several Marimo moss balls + more frequent water changes (maybe a snail or ghost shrimp eventually if I can afford it). Do you think this would be ok, or should I just stick with the filter and hope my betta gets used to it?
I think you’d be better off going without the filter in a small tank, and doing as you said above.
Hi Bryan – We’ve had our Veiltail Betta (Simon) for 3 months. His fins started looking raggedy (kind of stringy) in the last 1-1/2 months. He’s in a 10 gal filtered tank, and was treated with API’s FungusCure. We did two treatments, and have done two 25% water changes. His fins are still looking kind of stringy, but don’t want to over medicate. There are too many opinions on treating fin rot. What should we do. He does like to swim thru his filter waterfall -could that be it? Thanx, Donna.
Hi Donna – In that size tank, I don’t think it’s the filter unless it’s creating a lot of current in all areas of the tank. Do you have plastic plants? Make sure there is nothing sharp in the tank that Simon may be cutting or tearing his fins on. Next, make sure the temperature of the water is 78-82 degrees Fahrenheit, and if it’s not you need a heater. If all that checks out, test your water with some aquarium test strips to make sure there is 0ppm ammonia, as fin rot is also caused by dirty water.
So many questions! I recently put my Betta in a 5 gallon aquarium. I put aquarium rocks in there. Do I need to make sure all debris is gone from the rocks at all times? I have a sponge filter. It’s impossible to keep debris from them. Should I take it out. They’re those small rocks you buy in a bag. Also am I supposed to change the water every week even with the filter and I have to replace the sponge every 3 months? My fish is 2 years old. I had it in a large vase with a plant and now that I have a tank it seems happier but now I am worried about the rocks and filter I have a tank heater and I’m going to add live plants. I did notice the fins don’t look as full as before. Maybe it’s the rocks?
You don’t need to make sure that all debris is constantly removed, it just helps to keep you water cleaner for longer if you remove excess food and poop. Sponge filters are great, I would leave it in. A 25% water change once a week is ideal. Remember, the change in habitat can cause some initial stress too.
I am a newbie newbie newbie to any type of pet! If it were up to my kids we’d have every pet in the world- but Pets scare me. I am not confident in my abilities to care for them (nor my desire for constant upkeep). I agreed to a fish and am always worrying about something being wrong. First, our beta fish only swam at the top, then we realized the water was too cold and got a water heater. It’s been almost a week with the water heater and the water is looking gross! I want to enjoy the fish without a ton of maintenance. Cleaning the tank weekly in my opinion is too much maintenance (soo stinky!) So is buying a new filter every week. So frustrated im not doing the pet fish thing right. Any suggestions?
What size tank Krista? The larger the tank, the less maintenance you’ll need to do. With a 5-gallon heated and filtered tank, you should only need to do about a 25% water change per week and filter media replacement per your filter’s instructions. Items like a gravel vacuum can make things easier, and live plants can help keep the water clean too.
Hi,
I would like to buy a new heater for my 3 gallons for my betta fish. I got Moonlight as a baby and he is growing well however not sure the heater works great as it keep changing the light red to green. Also wondering what type of thermometer I could position on the glass maybe to make sure indeed the water is at 78 average? Many thanks for your help.
If your heater has a built-in thermostat and the switching of the lights means it’s either heating or not, then that’s normal. You can purchase a thermometer with a suction cup attached to it for a few dollars that would help monitor the temp.
I am considering buying a betta fish and 2.5 gallon tank. I have read that certain aquatic plants are effective as a “natural filter”. Would this effectively replace a synthetic filter? I would still feed the beta properly.
If you go with a 2.5-gallon tank I would not use a filter other than a sponge filter to avoid creating a strong current in a small tank. Plants do certainly help, but I wouldn’t say they completely replace what a filter can do. Keep some test strips in your supplies so you can test the water periodically to ensure the parameters are within the safe range.
I have had my beta for 2 years now. He is in a one gallon tank, I thought that was a big size tank since the one the store recommended to me was a third of that size. His tank is unfiltered and has no plants in it. He has recently been seeming sad and not moving as much. I want to switch him to a bigger tank with a heater and plants, possibly a filter as well but I am afraid that it might shock him and make things worse because he has not had those things for two years. Is there a way to make the switch that will be beneficial to him? I don’t want him to be unhappy any more. Thank you for the post, I look forward to hearing your advice.
Hi Megan – I’m really glad to hear you’re learning from the information and want to provide him with a better habitat. Him not moving as much lately may be related to his age. Betta fish typically live 2-4 years in captivity, and they are usually 6-12 months old when you purchase them as adults from pet stores. The life span can also be shortened from less than ideal conditions. With that said, you could certainly introduce him to a larger tank with plenty of fake or live plants and hiding places to allow him to hid in and feel safe. Betta fish can also become bored in their tanks, so it may be beneficial to introduce some change. Id recommend a filter if you go to a tank larger than 3-gallons, just ensuring it’s not very powerful and can be adjusted or baffled. Also, you need to make sure to acclimate him to the new water and temp of the new tank, and ensure the new tank is heated as well.
Hi Bryan,
I first got introduced to Betta fish when I bought one of these:
https://backtotheroots.com/products/watergarden
Have you heard of them? They make it sound like the plants clean the water and all of your problems are over. Not so! I had seeds slip into the main tank and make an absolute mess. Also, isn’t 3 gallons quite small for a Betta fish?
Thanks,
Nicole
Yes, I have seen this tank and many others that are similar and make similar claims. It’s a cool idea and is contemporary, but as you said it can create some problems – especially getting necessary equipment in there like heaters and filtration. And unfortunately no, the roots or plants on top on their own will not be enough to keep the water clean. The tank can work, it just requires some extra work. Partial water changes will still be required. For size, 2.5-3-gallons is the minimum size I typically recommend for a betta.
Hello! I have just bought a new fish tank and it is 1.5 gallons. I am wondering if I should use a filter for it and if so what type of filter. As of right now, I have one but I am not sure if the current will be too strong. Also, my tank is crowded and doesn’t have that much room for a bigger filter. What should I do? I also don’t want to buy a bigger tank but if that is absolutely necessary, I might.
Thanks!
I recommend 2.5-gallons as the minimum size for a betta fish habitat, and power filters only in tanks that are 3-gallons or larger because of strong current concerns. I would upgrade to a larger tank and use a sponge filter setup with aeration pump if it’s under 3-gallons.
But without changing the tank, should I get a filter?
I wouldn’t as it will further displace the volume of the water in the tank to well below the listed capacity. Without changing the tank, you will need to do frequent partial water changes and consider a live plant like a moss ball to aid in cleanliness and oxygenation.
What if you have a baby betta? Mine’s about 1 inch right now. Can I keep her in a smaller tank until she gets bigger?
Yes, it’s actually required. Baby bettas should be housed in 2.5-gallons to 5-gallons and have no power filters.
Hi Bryan! I also have a baby betta at about an inch in length. I was gifted a Tetra Whisper in-tank filter (up to 10 gallons, though my betta is in a 5 gallon). I haven’t been running the filter since she’s so small, wondering when would be a good time to start running it, or if you think this specific filter would be too strong for bettas in general. Thanks so much!
I wouldn’t introduce a filter until they were around 6-months old. There are a couple of concerns with that filter – 1. You cannot adjust the flow, 2. The intake area could present a problem if it’s very strong and the betta could accidentally get sucked up against it and not be able to swim away. I would look into a sponge filter setup if I were you, or think realistically about how you would baffle the flow of the water falling into the tank and restrict that intake area.
Hi Bryan,
I have been reading your website extensively, and scouring the internet for info on our Betta fish. I bought two 1 gallon tanks for my kids two betta fish, upon the advice from the big name pet shop. I was told that they would be fine with a hiding spot, plants, substrate. I bought them over the summer. They were happy campers for months, swimming around, showing off. Good little personalities. Then, I noticed our smaller fish was not going to his food and seemed sad. I ran to the computer and read, and read, and tried to identify his illness. Well, I have come to the conclusion that is only illness is COLD! I put two and two together, and he started to decline when it turned into winter here. The only thing he’ll eat right now is a small bit of pea. I am rushing to get the right supplies for these guys before something even more awful happens. I have settled on the Fluval Spec III (one for each of them of course), a Hydor 25w heater, Purigen filter material (I have no idea what that is but it seems to be in a bunch of reviews), and Luffy betta balls. Am I missing anything?? My biggest question is this: people have mentioned “cycling” the water before adding fish. I have read so many articles and I don’t understand. I can’t just put the fish in the tank like I did with this one? Honestly, if Petco had prepared me properly, I would have decided on not having a pet at all. But I am trying to be responsible and make sure the fish have a good life now that I have them. Please help! Thank you!
So sorry to hear about your experience thus far Julia. You are now on the right track, yes, and that sounds like a good setup for them. The only thing you may need to be careful with is the flow-rate of the filter into your tank on the Fluval III. Even though it’s adjustable, adding a Fluval pre-filter sponge to the output tube inside the tank will slow it down so there is little to no current (which betta fish require to avoid stress). You could also add a tall decoration or plants up close to the output to slow the flow as well. Cycling is going to be out of the question for you since you already have the fish, so you may want to pick up some “quick-start” which will add beneficial bacteria to the tank and speed up the process for you to acclimate them into the water on the same day or 24 hours later. It’s not ideal, but it’s better than their current living condition. Make sure to acclimate them into the new tank (float them in a bag or cup) for 20-30 minutes to get them used to the new tank’s temperature. Here’s my guide on acclimation, if you need it.
I have a 10 gallon tank with pathos vines, 1 betta and 2 snails. Heated with an old style rock/sponge filter.
Do I really need the filter or just a small air stone?
If your water parameters are fine and they don’t spike rapidly then it’s completely up to you. A sponge filter is generally more ideal as it produces little to no current which is favorable for bettas.
I have a 1 gallon tank with a filter included but the current seems to strong and I think is stressing out my betta. What type of filter should I get? A sponge filter?
Yes, a sponge filter, although you should upgrade your tank to at least a 2.5-gallon for a betta fish when you can.
We have a dumbo half moon in a 3.5 gallon tank. We have a heater in the tank. We have had him 2 weeks and he is declining. He keeps fins clamped and stays at top. We had a beta several years ago in same tank with no filter but lived in different house and climate. How do I add a filter to his tank if he is already there? We have done 2 partial water changes and he does ok a few hours right after we change it. I just don’t know what to do about cycling a tank when we already have a fish in there. 🙁
Is the filter producing too much current and stressing him out? Ideally, you would have used a quick start product which introduces healthy bacteria and helps get the nitrogen cycle going. Clamped fins are a sign of stress from the water parameters (ammonia, pH etc.), water temp, or environment.
Hello,
After reading this very helpful article I just wanted to say thank you. In my situation my Betta is currently experiencing constipation. I did an Epsom salt bath for him, but now him being in his 5 gallon I’m concerned about leaving the filter on since he’s already having a hard time swimming. Would you recommend no filter for now until he’s done healing? I don’t want him to drown either. You response would be greatly appreciated.
Sincerely,
Stina
Happy to help Stina! You could go that route, but if you turn your filter off, you’ll have to perform more frequent partial water changes. Alternatively you could keep the filter on, but try and baffle it using a pre-filter sponge or using decor and plants to slow the flow as it enters the tank.
Hey there! So I had my last Betta in an unfiltered 3-gallon tank planted with java ferns for about 4 years! After he passed I got another Betta but for some reason he seems to be putting out more waste than the other did so I was looking to get him tank mates of some kind to help keep it clean. I had snails before for a while but they littered my tank with hatched eggs, like HUNDREDS. Any thoughts on some snails or some type of shrimp that will be fine in a filterless tank? Thanks in advance!
Black racer snails or mystery snails are good options.
Bryan,
Need your advice. Yesterday I adopted a 6 year old betta who has lived in a 6 gallon unfiltered tank with heater all his life. I plan to continue without a filter, change 2 gallons per week, and 100% once a month. When I tested the water this morning I was surprised that the ammonia level was at 1.0. Is this usual? What should I do? I did a 100% water change yesterday. I added Prime to the new water.
Shirley
Ammonia should ideally always be at 0ppm. Spikes can happen from not having beneficial bacteria in a freshly setup tank. Doing partial water changes and adding fresh water will lower the levels. In a tank that size, and with proper partial changes, you may not need to do the 100% change as often as that depending on habitat cleanliness or algae issues.
I have a 29-gallon tank with a single betta in it. I was wondering if I even need a filter as I have an Aqueon 50 at the moment and I think it’s too strong. He is struggling to swim about and mainly sticks to the one end of the tank but will come and investigate if I turn off the filter.
While you don’t “need” a filter, they do help keep a healthy nitrogen cycle and good bacteria. Can you use decor or a pre-filter sponge or anything to slow down the flow into the tank? Regardless, you’re right, I would turn it off for now until you figure something out with the filter or get an adjustable one as it appears to be stressing him.
Hello Bryan. I have a 1.5 gallon tank which I know is absolutely too small for a betta. I will be getting a bigger tank as soon as I possibly can. But we did have a betta which we unfortunately lost recently. He got stuck behind the hang on the back filter. I was wondering if you could recommend the best filter for this size tank due to my 3 year old saying she wants her betta again.
A sponge filter is the best for smaller tanks, but at that size you could just go without a filter altogether and do more frequent partial water changes until you get a new habitat. The more items you place in the tank, the more water is displaced. So after adding decorations, plants, filters etc. you now may only have 1-gallon of actual water in the tank.
Hello,
I bought ‘Moonlight’ last july as a baby. I placed her in a Marineland 3 gallons aquarium with pump and heater to keep her at the temp she needs. I have been using 2 java ferns in the corner of the flow coming from the pump and I have used three small marino balls and one big one. Every week I would test her PH, Amonia, Nitrite,Nitrate…all was well I would do a 25% water change. Feeding wise she grew up on shrimps and blood worm with one day fasting and one day with 1/4 boiled pea which I would typically do on Saturday then Sunday would test, and clean water. I also made sure to clean her filter by placing it in her tank water I had taken aside of (the portion I was going to replace). She has Led lights and I have her on a 8am wake up, 7Pm moonlight setting after dinner and 11pm night time.
All was well she grew to be blue (was a light pink baby) with some soft green and pink. She has been very active recognizes me and plays. But a week and half ago suddenly her ammonia was really bad. I removed plants I cleaned there didn’t seem to be much debris in there so I was confused on how this could have happened.
It took awe two trials to figure out courant seems lower than usual and so suddenly I looked on the side where the pump is which I admit I never looked at. every thing I learned I learned from your forum (thank you!) but I guess I missed the check the pump and clean as necessary. Needless to say the pump was filled with crap and the bottom too so I had to empty it which meant emptying her water again.
I bought a new rio 50 pump after reading info on people who have the same aquarium. I also bought some product to give to try to reduce the ammonia and some bacteries to help start the tank faster. I fed her vey little and removed plants a few days after installing the new pump I tried my new plants same as usual. 48 hours later, today, I just tested and I already new something was bad again because the marino balls becomes yellowish if too much ammonia.
I’m at a complete lost!! Can you please help me?
I have had my betta for 3 months now. Started with a tiny tank then upgraded him to the TopFin BettaFlo tank but found it difficult to see him and clean due to its cylindrical shape. So upgrade again to a 9gal fluval flex. He is NOT happy in there. I unplugged the filter to stop the current but he is still hiding and stressed. Anything i can do to mod this tank to make him more content or downgrade back to something that is made for bettas (they all seem so small)
That is a big upgrade in size from what he is used to. You may need to heavily add plants and decoration in order to allow the betta to feel safer without so much open water. I personally own a Fluval Spec V – 5-gallon and feel it’s perfect. You could also look into a tank divider and have 2-bettas one on each side so they would each have 4.5-gallons of space. As for the filter, you’ll want to purchase a pre-filter sponge to cover the water spigot going into the tank to baffle the flow and slow it down.
I am temporarily housing a betta in a 1 gallon for a few paychecks. It was an emergency tank purchase and was the biggest available within my post-bills-paid price range. It’s a minibow with an included filter, so should I remove the filter and just do more water changes? Again, this is a temporary situation and I will be upgrading to a larger tank. I am very fortunate and my room temperature actually stays ideal for bettas. Without heaters all of my tanks are at 78-80 degrees at all times. Winter I will be investing in a few more heaters to go around.
Yes, do not use a filter in a 1-gallon tank.
How often should you cycle and do a complete water change for a 2.5gallon filtered (sponge) tank? Btw, it houses 2 male bettas that were from a community tank in the pet store. They don’t seem to fight…? Pet store employee said they were community bettas. After reading your site, not sure now if that’s true.
Just wanted to update that one of the bettas attacked the other one. I got duped by the pet store.
Yikes, I have heard of situations (rare) where two bettas do get along but I don’t recommend it for your exact outcome. For a complete water change it will depend on the condition of your individual tank. If you keep up on your partial water changes and other maintenance you may only need to do one every 1-2 months. Some people also go longer unless algae or other problems arise.
Thank you!! I’m now taking care of 2 2.5 gallon tanks because I don’t have the heart to get rid of one of them. How did they get along when they were in the pet store? They were all housed in one tank!
I’m not sure to be honest. I assume that tank was a lot larger in size, had lots of hiding places and likely had other species in there as well so the two bettas weren’t always in visual contact with each other.