How Often To Change Betta Water

Betta fish are the colorful floaty fish that you often see sold in small cups in pet stores.

Their scientific name is Betta splendens but they are also referred to as labyrinth fish and Siamese fighting fish.

How often to change betta water

The fish are native to the continent of Asia and live in shallow waters and slow-moving streams. Like humans, betta fish are diurnal, meaning they are awake in the day and asleep at night. 

They are often treated poorly in the animal trade supply chain and can be very traumatized because of this.

They have also been observed to suffer from depression and need a lot of mental stimulation in their environment. 

It is important to change the water of your betta fish’s tank regularly to ensure they remain healthy. This will stop harmful ammonium and nitrate levels from building up.

How often should you change the water?

How often to change your betta fish’s water varies according to the tank size.

If you have a very small, 1-pint jar this should be changed every day. We do not advise keeping a betta in a bowl this size. 

If the tank is 1 quart, this should be changed completely every other day. A half-gallon bowl should be changed completely twice per week. A 1-gallon tank should be changed completely once per week.

Larger tanks of 2 to 3 gallons (small home aquariums) should only ever have 50% of the water changed at once. This should happen once per week.

A large home aquarium of 5 to 10 gallons should not have more than one-quarter of the water changed at any one time.  (This is the smallest size of tank I recommend you keep a betta in.)

This should happen once per week, meaning that the entire tank gets replaced with fresh water once a month. 

The exception to this is if you are raising newborn and young betta fish. In this instance, you should change the water every day ideally. This kind of environment will help your betta fish to grow optimally. 

The most important factor to observe is the ammonia level in the tank’s water. This is toxic to fish and you should purchase test strips to keep an eye on the water concentration. 

When else should the water be changed?

If you are using water-soluble medication you are likely to need to change the water in the tank more frequently.

There are some medications that are more effective in clean water and in this case, they should be changed every 24 hours. 

If the water appears dirty, has a lot of scum, or is cloudy this is a good sign that it needs changing. Water like this is bad for the health of your betta and they should not live in this kind of environment. 

If you have overfed your betta and there is a lot of excess food in the tank this can begin to decay. This will cause the water to fill with toxins and should be avoided. 

What do you need to change the water?

You will need 2 large buckets. One should be completely clean and chemical-free - this will be used to hold the new water to add to the fish tank. The other bucket will be used to collect the waste water from the tank.

We recommend purchasing a tank cleaning siphon as this is the most efficient way to clean the tank. It drains water and vacuums loose debris without disturbing your betta fish.

You will also need some kind of water conditioning solution which helps to remove the chlorine and fluoride from household tap water. This is readily available online and at all good fish and pet stores.

You should also own a tank thermometer. It is important for the water in your betta fish’s tank to remain at a specific and stable temperature so that your betta remains healthy.

This thermometer will be used to ensure the replacement water is at the same temperature as the tank when added.  

How do you change betta water?

These are steps for how to change small home aquariums - i.e. without removing the betta fish. 

You should first remove the tank cover and any large tank decorations. These are things like decorative rocks and houses. 

Bring an empty bucket to the side of your tank and place one end of a siphon in the tank. If you do not have a siphon place one end of a hose into the tank.

You will have to pull the water up by sucking the exposed end and dumping the water into the bucket before it enters your mouth. 

Drag the end of the nozzle in the tank along the gravel at a 45-degree angle. This will agitate the rocks in the tank and help to release any decaying food collecting there.

Try not to remove too much water from the tank at any one time. This can stress your fish. Their unclean tank water is also a source of healthy bacteria for your fish and they need this to remain healthy. 

Throw the excess dirty tank water down the toilet to dispose of it. 

Fill a clean bucket with the correct amount of replacement water to fill the tank back up. Try to get the temperature to around 78 degrees Fahrenheit. 

Add some water conditioner to the water to make it the correct chemical balance to keep your betta healthy.

Follow the packet instructions for the quantity of conditioner to add and the specific instructions to follow. 

Return any rocks or decorative housing to your betta tank. Gently pour in the replacement water once it is at the correct temperature.

Do this slowly so that you do not harm your betta fish. Alternatively, you could use the siphon to ensure it is added at a consistent flow. 

If you have a filter in the tank, remove and clean or replace as necessary. Place the lid of the tank securely back on and plug in the filter. Turn on the heater and lights, and you’re all set.