Why Does My Betta Have White Stringy Poop? (Explained!)

Affiliate Disclaimer:

FishKeepingAnswers.com is reader-supported. When you buy through links on our site we may earn a commission.

It is easy to see why Bettas are so widely loved.  They are colorful, easy to care for and have tons of personality.  I have spent the last 20 years keeping and breeding Bettas, and over that time hundreds have passed through my fish room.  I have bred Bettas for fun, for competition and to sell to my local fish store. 

It is a Bettas hardiness that has no doubt contributed to their longevity in the hobby.  However, even a fish as hardy as a Betta can occasionally succumb to pests or diseases.  In this article, I answer the question ‘Why does my Betta Have White Stringy Poop?

There can be multiple reasons a Betta has white stringy poop, but the most likely cause is internal parasites.  Other potential causes include poor water quality, constipation, and being fed low-quality foods.  Working out why a Betta has white stringy poop is the first step to resolving the situation.

Reasons a Betta has white stringy poop

There are many reasons a Betta may be suffering from white stringy poop.  These include;

  • Internal parasites
  • Constipation
  • Poor quality diet
  • Incorrect water parameters
  • Bullying by another fish
  • Lack of food
  • Stress

Treating a Betta for Internal Parasites

Internal parasites such as tapeworms are the most likely cause of stringy white poop in a Betta.  Tapeworms are easily picked up by a Betta either at the fish wholesalers, in the fish store, or even once they reach our aquariums.  The problem is, Bettas will occasionally scavenge food from the substrate, and this is where they inadvertently eat the tapeworm’s eggs, which in turn hatch inside the Betta.

Once the tapeworm is living inside the Bettas digestive system it will consume much of the goodness from the food the Betta eats.  Eventually, as the tapeworm grows, it will end up consuming everything, meaning the Betta starves to death, even though it is eating.

Luckily for us, treating a Betta for internal parasites such as tapeworms is fairly simple.  There are a number of good treatments on the market, but I have had great success recently using Paracleanse which is made by Fritz.

I normally just order this pack from Amazon (it is the best value I have managed to find). Paracleanse is easy to use, you simply add 1 pack of Paracleanse for every 10 gallons (38 liters) of aquarium water on day one, then again 2 days later.

Treating a Betta for Constipation

White stringy poop can mean a Betta is constipated, but signs of constipation also often include a swollen abdomen.

Constipation in a Betta is usually caused either by overfeeding or by feeding cheap low-quality foods.  Low-quality fish foods are made with lots of ‘fillers’.  Fillers are anything that bulks out the food but offers no nutritional value to the Betta.

Bettas are easily overfed, especially by new Betta fishkeepers.  Because Bettas are so personable, new fish keepers often see them come to the surface to eat, and then give them too much food. 

To prevent overfeeding a Betta, try feeding them 3 or 4 times over the course of a day, but only a small amount of food each time.  When it comes to feeding Bettas, little and often is better than ‘all in one go’.  I try to feed my Bettas at least 3 small meals a day, and sometimes I might feed up to 5 times a day, but only a small quantity each time.

If you believe your betta is constipated, try feeding either live or frozen daphnia. Daphnia is a small, shelled crustacean that occurs naturally in waterways around the world.  When a Betta eats daphnia, the shells have a laxative effect, helping pass constipation.

Poor Quality Betta Diet

If we want our Bettas to be healthy, colorful, and full of personality, we need to make sure they have a good quality, varied diet.  In my experience, the greater the choice of foods we give our Bettas, the better quality of life they seem to have. 

I like to feed my Bettas a mix of live foods, frozen foods, and quality prepared foods such as Vibra Bites from Hikari and Bug Bites by Fluval (I think I paid less than $5 for these ones on Amazon).  Both these foods offer Bettas a range of vitamins and minerals, although not all Bettas will eat them.

I like to feed my Bettas something different at each mealtime, so on a day when I feed my Bettas 3 times a day, I might give them Vibra Bites in the morning, Bug Bites when I get home from work, then live or frozen food in the evening.  To give an even wider selection of foods, I like to feed a variety of frozen foods, which often include daphniabloodworms, and mosquito larvae.

If you feed your Bettas the same, cheap food at every mealtime every day, there is a good chance your Betta will have white, stringy poop.  Try varying the foods and definitely consider adding at least one type of live or frozen food 3 or 4 times a week.

Incorrect Water Parameters

Although often considered a hardy fish, Bettas do like their water parameters to remain constant.  They don’t like fluctuations, especially if they happen quickly.  The ideal water parameters for Bettas are;

  • Temperature: 75°F – 80°F (23.5°C – 26.5°C)
  • Ammonia: 0 ppm
  • Nitrite: 0 ppm
  • Nitrate: 40 ppm or less
  • pH: 6.5 – 7.8
  • GH: 3-4 dGH
  • KH: 3-5 dKH

If your Bettas aquarium water doesn’t match the parameters above exactly, don’t worry too much, providing they remain stable.  A Betta could easily live in water with a pH of 8 or higher, providing it doesn’t fluctuate.

If you are unsure of your water parameters, I strongly recommend getting yourself a Master Test Kit which is made by API.  The test kit is easy to use, fairly accurate and doesn’t cost a great deal (check the latest price here).

If after testing your Bettas aquarium water you discover the ammonia, nitrite or nitrate is too high, immediately carry out a large water change (maybe as much as 75%) to lower the ammonia, nitrite, or nitrate levels in the water, then try to work out why the levels became so high in the first place.

Bullying by Another Fish

Despite their historic name of the ‘Siamese Fighting Fish’, Bettas are easily bullied and intimidated by bigger, more aggressive fish.  Whilst I always advocate keeping a Betta in a community tank with other fish rather than in a small bowl alone, we do have to select a Bettas tankmates carefully.

Bettas don’t do well with more aggressive fish like Angelfish or Tiger Barbs, and they certainly should NEVER be kept with another male Betta. I have had Bettas who were bullied by large Black Mollies, so whatever fish you have in with your Betta, take some time to observe the aquarium and see if your Betta is being bullied. 

Classic signs of fish bullying are if your Betta is being chased constantly or being pinned down by another fish.  Fin nipping is another sign of bullying as is denying the Betta food by chasing it away when food is added to the aquarium.

If your Betta is being bullied you will need to move either the Betta or the bully fish.  Stressed caused by bullying can kill a Betta surprisingly quickly, so don’t ignore the problem.

Lack of Food

If your Betta hasn’t eaten for a few days, perhaps because it has been in transit to you or to your local fish store, then it may well have white stringy poop simply because its digestive system is empty. 

If the Betta is new to you, try offering it some food, perhaps starting with something like live or frozen bloodworms.  If your Betta eats readily, give it a few hours, and then check back in on its poop.  Hopefully, things will be back to normal.  If not, feed a little more, then check back.


Any one of the points above can cause your Betta to be stressed and stress can kill a fish very quickly.  If you believe your Betta may be stressed, try to work out the cause of the stress and rectify the problem as quickly as possible.

How to avoid Bettas getting white stringy poop?

There are a number of things we can do to prevent our Bettas from getting stringy poop in the first place.

Quarantine New Fish

Quarantining new fish is something we should all do, but often we don’t.  If you are planning to add new fish to your Bettas aquarium, consider quarantining them in a separate aquarium for at least 7 days prior to adding them to your Bettas aquarium.  Whilst the new fish is in quarantine, treat it with medication for internal parasites, otherwise, you run the risk the new fish will introduce parasites like tapeworms into your Bettas aquarium. 

Whilst the new fish is in quarantine, take some time to observe it.  You don’t want to inadvertently introduce Ich or a similar disease to your Betta tank.

Regular Aquarium Maintenance

Carrying out regular routine aquarium maintenance such as water changes, gravel vacuuming, and servicing your Bettas filter can help keep the water parameters in check and maintain a stable environment for your Betta to live in.

I firmly believe, when it comes to Bettas water, stability is better than perfect, and maintenance helps keep water stable.

Avoid Under or Overfeeding your Betta

Over and underfeeding can both cause a Betta to develop white stringy poop.  Personally, I like to feed little and often.  If I had time I would feed my Bettas 5 or 6 times a day, just very small amounts each time.

My final thoughts on ‘Why does my Betta have white stringy poop?’

If you notice your Betta has white stringy poop, try to work out the cause. Solving the problem will reduce the chances of your Betta suffering any long-term ill effects.  

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James

Article Sources: