How to Help Your Sick Betta Fish

Betta Fish Diseases and Treatments

Educating yourself ahead of time and being prepared for how to deal with a sick Betta is the best proactive approach you can make in caring for your fish!

There are specific symptoms to look for, what causes the disease, and what the treatments are. Be aggressive, be proactive, and be patient when dealing with a sick Betta.

Everything to Know

betta fish diseases and ailments

We have compiled a comprehensive list of diseases that affect Bettas along with what the symptoms and causes are, and lastly, how to treat it.

The first line of defense in being prepared is to have a dedicated hospital tank set up that is separate from your Bettas tank.

The hospital tank serves as a quarantine tank for sick fish, a quarantine tank when you bring new fish home, and a place to put your fish when doing water changes or recycling your tank. 

What Causes Bettas To Get Sick?

  • Poor Water Quality is the  #1 cause of sick fish
  • Poor Diet
  • Overcrowding (too many fish)
  • Handling the fish
  • Incorrect water temperature
  • Adding new fish that were not quarantined for two weeks. New fish can be carriers of parasites and other sickness’.

Types of Illness and Diseases in Bettas

There are numerous ailments, illnesses, and disease that happen with Bettas.

  • Ich
  • Fin Rot
  • Swim Bladder
  • Fungal Infections
  • Velvet
  • Dropsy
  • Anchor Worm
  • Columnaris / Mouth Fungus

Poor Water Quality

betta tank clean water

The very first thing to check if you have a sick fish is the water quality. Make it a priority to keep your fish tank clean and healthy. Test your water regularly.

Important to Remember

  • Clean and Clear Water is BEST...Murky Green Water is BAD!
  • Fish Bowls are merely containers that are too small for fish and is nothing more than a confined container for polluted water. It is highly recommended not to use a fishbowl if you want your fish to live.
  • New Fish: never put a new fish directly into your existing fish tank. Always quarantine them in a hospital tank for two weeks. Parasites on the new fish will infect your entire tank and make your other fish sick as well.
  • Overfed fish produce more waste. More waste produces polluted water.
  • Don’t overcrowd your tank; two fish for every twenty gallons of water at the minimum. Overcrowding tanks cause more waste than the tank can handle. A certain amount of space in the tank is required per fish because of the oxygen content the fish requires. Too many fish depletes the supply of oxygen.

Diseases and Treatments

Ich - Highly Contagious

This disease is very common in Bettas and generally happens to new fish. The stress of the car ride home and being introduced to a new habitat causes it to be more prone to disease.

Other stresses such as a drastic change in water temperature or maintenance of tank can affect your fish as well. The best thing to remember is to do all that you can to relieve undue stress on your Bettas.


  • Ich parasites are found in water that fish are in. It is many times unavoidable when introducing your new Bettas into your aquarium or tank that residual water from the original tank it was previously in will find its way into your tank.
  • After you have introduced new Bettas into your tank, be vigilant in testing the water to maintain good water quality.


  • Small granules on fish that appears to be like salt grains
  • Betta is breathing heavily
  • Betta rubs up against the wall of the tank or other objects in the tank


  • Before treating, slowly warm the water temperature to 76-80 degrees (F.) The increasing warmth will cause the parasites to detach from the fish.
  • Remove plants from the tank. Treatment will damage and even kill plants.
  • Do a twenty-five percent water change. Test water to ensure all levels are optimum.
  • Add aquarium salt (.03% concentration): one teaspoon for every gallon of tank water.
  • Over the next twenty-four hours, repeat steps 1-4 every twelve hours (total of 3 times.)
  • Allow the aquarium salt to remain in the tank water for two weeks. After that do a 50-75% water change.

Problems with Buoyancy - Not Contagious

There are several causes when your Bettas cannot float correctly. If your fish is floating upside down, swimming sideways or appears to be bloated, it’s best to narrow down the cause and then treat accordingly.


  • Overfed
  • Poor Diet
  • Constipation
  • Flatulence
  • Swim Bladder Disease


  • Swimming sideways
  • Swimming upside down
  • Looks enlarged or swollen


For Constipation

  • Cooked peas help relieve constipation. Cooking the peas makes them soft. Make sure to remove the outer peel. Don’t feed more than 1-2 peas per day.

For Swim Bladder

  • Clean the tank to lower levels of bacteria.
  • Raise water temp to 70-80 degrees Fahrenheit.
  • Let fish fast for three days. Monitor to see if fish improve.
  • If symptoms persist, get an antibiotic from pet supply store.

Fin / Tail Rot - Contagious

Fin Rot and Tail Rot in Bettas are apparent when you notice your fish’s fins or tail appear as if they are frayed or torn. If treated promptly the tissue can grow back, however, if the rot is in the immediate area of the body, it will not grow back and can even enter the body of the fish which is fatal.


  • Stress
  • Poor water quality
  • Overcrowding (too many fish)
  • Sudden water temperature change


  • Fin / Tail appear frayed, torn or ragged
  • Edges of fin / tail become white from bacteria eating away


  • Remove sick fish from the tank and place in a separate container.
  • Using a fresh, clean fishnet, remove all other fish from tank and place in a separate container (do not put them in with sick fish). Fin Rot is contagious, so make sure you do not use the same fishnet that you handled the sick fish with.
  • Thoroughly wash (using hot water, no soap) and clean tank as well as all tank decor.
  • Wash gravel
  • Do a water change: 100% using conditioned water.
  • Use new tank water to rinse the filter. Place filter into the tank.
  • Check pH levels before placing healthy fish back in.
  • Slowly add all fish back into the water.
  • Monitor the sick fish for a few days and if it does not improve, add a fin rot treatment (you can purchase at a pet store.)

Fungal Infection -  Highly Contagious

Fungal infection is contagious to the other fish in the tank. If not treated quickly, you can end up losing your fish. This infection can become a secondary condition of Bettas  that have already been sick from something else.


  • Stress
  • Lowered immune system
  • Poor water quality


  • White growths on body and fins


  • Because this is highly contagious, the sick fish need to be removed from the tank and placed into a hospital tank.
  • Purchase a fungal treatment at your local pet store.
  • Treat your sick fish (in the hospital tank) with the fungal treatment.
  • Monitor the sick fish for a few days and if no improvement, do a salt bath treatment.
  • When your sick fish has healed, transfer it back to the main tank.

Velvet Disease -  Highly Contagious

Velvet disease is parasites that resembles small dust particles on the fish. It generally begins to develop on the spinal area of the fish, and because the parasites are so tiny, it’s difficult to see.


  • Usually brought into tank water by new fish
  • Stress caused by poor water quality


  • Film (pale yellow color) develops on fish
  • Fish rubs against tank wall or other surfaces
  • Clamped fins
  • Heavy breathing
  • Weight loss


  • You can treat with a medication called formalin (available at a local pet store.)
  • Use caution if treating with formalin. It can easily burn your fish’s fins.

Dropsy Contagious To Other Fish

This disease is very distinct in making the fish have a pine cone appearance. Unfortunately, by the time the fish presents with this appearance, it’s untreatable.

Dropsy is painful, and you may find that making the choice to euthanize your fish is the best humane thing to do.


  • Kidney dysfunction (renal failure) causing fluid buildup
  • For older fish, prolonged exposure to low temperatures
  • Bacteria in kidney
  • Parasites in kidney


  • Bloating
  • Pinecone appearance from fluid retention pushing scales outward
  • Eyes distended from the socket
  • Body or fins develop redness


  • You will need to purchase medication for treatment at your local pet store.
  • Following dosing directions closely.

The Hospital Tank

The hospital tank needs to be separate from your regular fish tank and is to be used only for quarantining new fish, separating sick fish from healthy fish and for treatment of sick fish.

Setting up a Hospital Tank

  1. Set up a separate tank with a filter system. Include plastic plants, rocks, etc. to provide hiding places for the fish (this helps calms the sick fish.)
  • DO NOT place any substrate in the hospital tank on the floor of the tank. Loose food gets caught in it causing water quality to decline rapidly.
  • Transfer some of the established bio media from the filter in the main tank into the hospital tank. By doing this, you introduce the media to the hospital tank that will help to maintain the nitrogen cycle.
  • Set the filter on the lowest setting. This will ensure that the movement in the water is at a minimum. Rapidly moving water can add stress to the already sick fish.
  • Using a mesh bag, place some of the main tank’s substrate into a bag and put directly in the hospital tank.
  • Turn on the heater to reach ideal water temperature. Bettas require a water temperature of 76 - 81 degrees (F.)
  • Transfer sick fish over to hospital tank using a net (not your hand.)
  • Proceed to treat sick fish in the hospital tank.

“Swimming On” our next article

Join us now as we continue on in our Betta series where we will dig deeper into the fascinating world of the Betta fish.

Next: “Purchasing a Betta.”

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