2 Main Reasons for White String Hanging From Fish

When you notice a string hanging from a fish, you may be nervous and wonder if it is dangerous for your fish.

The good news is that it’s not something that can harm your fish. The primary causes are an unsafe meal supply or parasites.

Whatever it is, you can easily treat it. You will easily handle it after reading this article. Now, let’s scroll down to read more information!

Reasons for White String Hanging From Fish



string hanging from fish

Parasitic infections can also lead to a string hanging from fish. It includes tapeworms, Hexamita, and roundworms.

You will easily recognize this situation since the string attaching your fish will turn into a more yellow color and be long, stubborn, and stringy-like.

The poop of fish is typically light and should reach the substrate immediately when it leaves your fish’s body. But when your fish are struggling with parasites, their poop might move.

Loss of appetite or sluggish behavior are also signs you should look out for. Your fish also becomes paler, while their head might become darker.

Common Causes

The truth is that parasitic infections aren’t prevalent with fish, especially in the pet ones, unless they were brought from outer waters or have been exposed to another caught-in-the-wild individual.

Otherwise, your fish is less likely to get a parasitic infection in your aquarium.


One of the best treatments for fish infected with Parasites is to use Flagyl or Metronidazole. But we recommend checking with the veterinarian before giving fish any kind of medication.

Constipated Fish


You can tell that you have constipated fish if you detect long, bloating, white string-shaped poop hanging from them.

If the health of fish is in good condition, their feces should be in tiny pieces which will rapidly drop to the bottom before dissolving in the tank water quickly.

Furthermore, your fish might lose appetite, behave oddly, and seem lethargic.

If you don’t treat your fish’s constipation in time, your fish may have trouble digging, and they might just lay in caves or on the substrate.


Goldfish in an aquarium with bubbles in the water

A Lack of Fiber

A lack of fiber in a fish’s diet can cause constipation. Fiber is essential for keeping the digestive system healthy.

The digestive system will not function correctly without adequate fiber, and constipation may occur.

Physical Deformities

This factor can make it difficult for your fish to digest its food correctly and lead to constipation.

Some deformities are intestinal blockages, kinked intestines, and tumors.

Spoiled Or Stale Fish Food

Stale food does not provide the nutrients that fish need to stay healthy, while spoiled food can include harmful bacteria that can make fish sick.


When you feed your fish overeating, the undigested food might sit in their stomach and lead to constipation.

If you are overfeeding fish, it is easy to see uneaten food landing on your tank’s bottom.

Temperature Changes

When the tank water is so cold, it can slow down the metabolism of fish, making it challenging for fish to digest their food appropriately.

If your tank water is so warm, it might speed up fish metabolism, causing them to deliver more waste.


Let’s start by adding laxatives to your fish’s diet in addition to a higher-fiber food. Avoid giving your fish frozen food, pellets, and flakes, which could worsen the situation.

In addition, while handling fish constipation, you should maintain a regular diet and not add any other nourishment than the existing one.

Good high-fiber diets for your fish should include tinned peas. In addition, it is okay to add some plants like Elodea, Egeria, and chitin food, such as lobsters, shrimps, or minor insects, to your fish diet.


If you keep freshwater fish, you should use nori instead of terrestrial plants. It is extracted from marine algae, making it the best edible seaweed you have.

It is a cost-effective option; you can quickly find it online or in your local stores.

If you keep fish like parrotfish and surgeonfish, you can try to add green food to your fish diet.

It might include sliced cucumbers, some plants like Canadensis and Egeria, and smaller chunks of lettuce and spinach, etc. In addition, avoid feeding your fish pellets or flakes.

Many fish like goldfish, Lionhead, golden cichlid, and Metynnis argenteus are fine with vegetable flakes, vegetable flakes,  terrestrial plants, and green food such as chickweed, squash, peas, and lettuce.


Is String Hanging From Fish Dangerous?

In most cases, it’s not life-threatening to your fish. But you need to treat it promptly to ensure your fish stays healthy.

How Long Does It Take for My Fish to Poop?

Fish poop may hang from the fish’s body for one or two minutes before falling. If it doesn’t fall for a considerable time, it could be a sign of constipation.

Why Does Goldfish Have Poop Hanging Out?

The key reason is that Goldfish have been overfed. So if you think you are overfeeding Goldfish, fasting them for one or two days is essential to help the digestive system clear.

What Is Hanging From Guppy?

Camallanus is a common parasite in guppies. It can reach up to 0.8 inches in length and hangs out from the anus of fish.

It features an orange and brown color and has motion similar to worms.

Why Does Guppy Feature One White String?

Bad quality water can sometimes lead to guppies having white stringy poop

Bad quality water can sometimes cause a guppy to have white stringy poop. High nitrate levels or an ammonia spike can also majorly affect guppies’ health.


String hanging from fish is not a dangerous symptom, and you can easily get rid of it through the tips we have mentioned.

So the next time when you notice a string hanging from a fish, you’ll know what you have to do to help them.