How Long Should Water Sit Before Adding Betta Fish

Last Updated on October 6, 2020

One important aspect of the fish keeping hobby is maintaining good water quality for fish tanks.

Fish need an environment that has excellent water conditions for them to thrive. You can do this through water changes in our fish tanks. This ensures that toxic substances especially ammonia do not accumulate and pose any threat to our fish.

But how long should water sit before adding betta? Find out below.

How long should water sit before adding fish?

A good practice is to let water sit for at least 24 hours before using it for fish tanks. This will let chlorine to air out from the water. Water treatment facilities add chlorine to tap water processing so that the water is safe for human consumption. Chlorine is volatile and will leave the water after at least 24 hours.

But, chloramine is also usable by other water treatment facilities aside from chlorine. Chloramine is less volatile compared to chlorine and will not just evaporate on its own in 24 hours. Chlorine and Chloramine are substances toxic to fish. These can damage their gills and lead to death.

It is better and more convenient to use commercially available water conditioners. They manufactured these to detoxify chlorine, chloramine, and heavy metals from tap water. Water conditioners are fast-acting and the treated water is used for fish immediately. Each manufacturer has a certain measurement to follow so will read the instructions.

Betta fish are not different from other freshwater fish. Chlorine and chloramine will harm them. Aside from these substances, you should also be conscious of the fact that ammonia will accumulate in a fish tank.

Ammonia accumulates from the fish’s waste, uneaten food, and other rotting material. There is constant water turnover in their natural habitat where these substances do not have the chance to accumulate and harm fish. These are vast rice fields, streams, and irrigation canals. You can simulate this water turnover through water changes with conditioned water.

how long should water sit before adding betta

How often should I change betta water?

For a Betta fish in a filtered tank, a 20-25% partial water change at least once a week is good. For non filtered tanks it would require more frequent water changes especially for containers that are small. We recommend 5 gallons as a minimum for a betta fish. If you put your Betta in a container smaller than 5 gallons without a filter, then it may need to be as frequent as every other day. This is to make sure that ammonia levels will not accumulate too high and poison your Betta fish.

A filter has components such as the sponge or a cartridge where beneficial bacteria can accumulate. These beneficial bacteria help in keeping ammonia levels low. Nitrosomonas will consume ammonia and convert it to Nitrites which is a little less toxic. Nitrobacter will then consume Nitrites and convert it to Nitrates which is far less toxic for fish. This is why it is important to “cycle” a tank. Let the beneficial bacteria that run the nitrogen cycle to get established before putting in fish. Live plants can use nitrates to grow. It lowers when you do water changes.

A test kit comes in handy if you really want to know the water parameters in your Betta fish tank. This will let you measure the level of ammonia, nitrites, and nitrates. You can just do regular water changes to make sure that the water in your Betta fish tank is always in good condition.

How to set up a betta fish tank?

Choose a tank is at least 5 gallons

You will have fewer problems in the long run if you get a 5-gallon tank instead of a smaller container. This will let you provide better living conditions for your Betta fish. Water parameters will not fluctuate too much with a 5-gallon tank set up compared to a 1-gallon bowl. Be sure to have a lid because Betta fish may suddenly jump out of the tank.

Get a sponge filter

A sponge filter is suitable for a Betta fish because it will not create a powerful flow that will keep your Betta fighting against the current. Betta fish will get too exhausted if the flow is too strong.

Get an aquarium heater

Betta fish need temperatures to be within the tropical range of 78 to 80 degrees Fahrenheit or 26 to 27 degrees Celsius. This optimal temperature range will keep them healthy. They are tropical fish and will become prone to disease if the temperature is lower. An aquarium heater will keep the tank water stable and constantly at this range.

Consider getting an aquarium thermometer

This will show you if your Betta fish tank’s water is within the optimal temperature. Too high and Betta Fish’s life will shorten because of a faster metabolism. Too low then your Betta is prone to disease.

Gravel or Aquarium Soil

Gravel would be a splendid choice if you are not planning to keep any live plants that need to in the substrate. Choose smooth gravel that will not damage the delicate fins of your betta fish. Gravel will be easier to clean too. Aquarium soil is needed if you want a planted tank though. Aquarium soil will not harm the delicate fins of your betta fish. There are some live plants that do not require to be planted into the substrate such as anubias and java fern.

Light Source

Choose a light that will enable you to see enough. Your Betta fish will not appreciate too bright light. A dimmable feature would be great. If you decide on a planted tank, then choose lights suitable to grow plants too.


Avoid sharp objects. That would guide you in choosing any rocks, caves, underground castles, submerged ruins, and treasure chests. It depends on your creativity. Just be sure it’s not sharp. Artificial plants made of silk are a pleasant choice. If you go the live planted route, then your betta fish will surely enjoy that! Real plants will recreate a wonderful underwater natural environment.

What is the best water conditioner for betta fish?


Water quality is a very important factor in the health of a betta fish. Excellent water conditions happen by following a regular maintenance schedule of partial water changes. This process is easier and more convenient by using water conditioners that render the water safe for your betta fish almost instantly.