How to Treat a Sick Betta Naturally

by Kevin

Betta Fish in Planted Tank

A sick betta fish is a sad sight for sure.

But there are things you can do to help revive your fish.

Steps to Treat a Sick Betta Fish

1) Shine a light on your betta fish and observe his or her behavior. Try to determine if your betta is stressed from water conditions or suffering from a disease.

2) Place your betta in a quarantine tank (your betta’s normal tank should be drained and cleaned).

3) Make sure the quarantine tank has a heater.

4) Dose your betta fish with medication.

The steps mentioned above are not the only way to treat a betta, and depending on what your betta fish is suffering from, you may need to do additional research to pin point the exact problem and find the appropriate medication.

These steps are what worked for me and I can only speak to my experience.

My Betta’s Cloudy Eye (Bacterial Infection)

Sick betta fish with cloudy bulging eye.

This is Marbles, she’s a female koi betta and one of the newest members of my betta crew.

I purchased her from a local pet store but I believe she was imported from somewhere farther away.

I picked her up as soon as I received a call that she had arrived at the store.

When I arrived at the store she looked healthy and appeared to be a strong swimmer.

I took her home and put her in a new tank.

Her tank was actually a quarantine tank because I quarantine my fish before placing them with tank mates, like shrimp.

Five days later, I noticed that Marbles’s eye was bulging out and clouded, as you can see in the picture above.

It looked bad.

Sadly, this experience is far too common when buying a betta from a pet store.

But, this doesn’t mean your betta fish is doomed.

Below is Marbles after receiving treatment for her bacterial infection; her eye is healed and appears to be working (I thought she might go blind in that eye).

Sick betta fish treated successfully, cloudy eye is gone and betta fish is healthy.
Marbles after recovering from cloudy eye.

Identifying signs of disease early is key and increases your betta’s chances of survival.

Natural Betta Fish Medications

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What I used:

1) Melafix

2) Aquarium Salt

3) Indian Almond Leaf

How I Treated My Betta with Natural Medication

These are the steps that saved my betta from cloudy eye:

1) I put my betta Marbles in a 5 gallon quarantine tank with a heater and no filter.

What’s a Quarantine Tank

A quarantine tank is simply a tank dedicated to isolating a fish from other fish.

If your betta is already in a tank by himself or herself, you will not need to isolate your fish unless you have live aquarium plants in your tank.

Some of the substances used to treat your betta fish (like aquarium salt) may kill your plants.

I chose not to use a filter because I did not want the medication to break down, but using a bubble stone or sponge filter is a good idea.

2) If your quarantine tank is the same tank your betta fish has always lived in, do a 70-80% water change.

3) Then add a capful of Melafix.

4) Each day, I added another capful of Melafix to the tank.

5) On the 5th day (after 5 capfuls of Melafix), I performed a 50-60% water change (the tank should smell like tea tree oil).

6) On the 6th day I added a capful of Melafix and also added an Indian almond leaf (to add tannins to the water) and a teaspoon of aquarium salt.

7) On the 7th day Marbles’s eye looked 80% healed.

8) I continued to add a capful of Melafix everyday.

9) By the 10th day Marbles’s eye had completely healed and I performed another 70-80% water change.

So why does Melafix work?

Melafix lists it’s active ingredient as “Melaleuca,” which is an oil extracted from Tea Trees.

Malaleuca or Tea tree oil actually has antibacterial and antifungal properties making it a natural and potent alternative for treating your betta fish.

The Melafix label states: “A safe, all natural way to treat bacterial fish infections. Also recommended for treating newly introduced fish to reduce risk of disease outbreak.”

Types of fish diseases that Melafix may be effective on include

1) Open red sores

2) Fin and tail rot

3) Body wounds

4) Cloudy eye

5) Pop eye

6) Mouth fungus

I was able to add quite a lot of Melafix to my tank (over the recommended dosage) and it did not appear to stress of harm my sick betta fish in any way.

Also, I added a plant (susswassertang) to the tank to see how it would react to the Melafix; the susswassertang looks great and seems unaffected.

I also added a teaspoon of aquarium salt to my tank when my betta’s cloudy eye began to get better.

What is Aquarium Salt?

Aquarium salt is made from evaporated seawater just like some food grade sea salts sold in grocery stores.

But, I assume, aquarium salt is manufactured to add the appropriate amount of salinity to your tank while grocery store salt is not.

And aquarium salt is not food grade (haven’t tried it) and should not be used for anything other than treating your tank.

API manufactures the aquarium salt that I used in my betta tank.

According to API, aquarium salt provides freshwater fish with electrolytes that promote fish health, improve gill function, and promotes disease recovery.

I have no reason to doubt that aquarium salt helps fight fish disease and aid in recovery and it seemed to help Marbles so I’m a fan.

Be sure to follow the dosing instructions: 1 table spoon for every 5 gallons or ½ a table spoon for every US gallon.

Also the salt does not evaporate after your fish recovers so be sure to do a few significant water changes to remove any excess salt.

Why Betta Fish Get Sick

Betta fish become sick for two main reasons, i) poor tank conditions and ii) invisible bacterial or fungus growth.

Poor tank conditions are fixable, and invisible bacterial or fungus growth can be managed with frequent water changes and adding live plants.

What do poor tank conditions look like?

i) The Betta Fish in a Cup

Perhaps the number one reason betta fish get sick is that betta fish are kept in tanks that are too small and/or rarely receive water changes.

At big box pet stores, betta fish are often kept in cups, and unless the person working in the aquatic department is really paying attention, these bettas tend to swim around in their own feces.

Cups that small probably should receive a water change at least 2 times a day, but I suspect that these bettas don’t receive a water change more than once a week because it’s a pain for an employee to dump out and then add water to 20 different betta cups.

So, water conditions become toxic quickly and the betta’s immune system weakens.

Then, bacterial and fungal infections run wild.

In my own experience, betta fish purchased from big box pet stores get sick more often than betta fish I’ve purchased at aquarium clubs.

I believe the reason that pet store betta fish tend to be more fragile and prone to disease is:

1) they probably spent significant time in transit before arriving at the pet store; and

2) instead of being given a dark tank to de-stress; the betta fish are put on display in brightly lit, rarely cared for, small cups.

The fish then slowly succumb to very treatable diseases.

ii) Invisible Bacterial and Fungus

The other common reason betta fish become ill is an outbreak of bacteria or fungus that goes unnoticed until your fish has a bulging eye or cloudy eye or his or her fins begin to rot.

Water conditions likely play a big role in allowing the bacteria or fungus to thrive because things like nitrates, waste, and other nutrients are constantly fluctuating.

This is something we all face as aquarists because the water in our tanks is confined rather than free flowing, as you would find in nature.

So, we aquarists battle to keep our aquarium ecosystem in balance.

If your water shifts in a way that is stressful for your betta, he or she may develop a disease.

The best thing to do is identify the type of disease your betta may be suffering from and place your fish in a quarantine tank (and definitely avoid putting your betta in a cup).

Betta fish are hardy fish and will recover most of the time if given the right medications and conditions.


You will not be able to predict or prevent all disease, but what you can do is make sure your fish has stable water conditions (a cycled tank with adequate heat and filtration) as well as weekly water changes.

Seeing your fish struggle with an illness is a stressful experience and is one most, if not all, of us fish keepers will experience at some point.

The best thing you can do is spot signs of sickness as early as possible and treat your fish with the appropriate medication and/or salt.

Having medication and aquarium salt in your aquarium supplies is smart and should provide you some peace of mind.

If your betta fish seems sluggish or is swimming on his or her side at the bottom of the tank, take a look at my article on determining if your betta is sick.

Let me know in the comments if you have ever used aquarium salt to treat your fish.

As always, stay zen aquarists.