Betta Tank Water Change 101: Everything You Need to Know About Replacing Tank Water

Aquarium maintenance isn’t exactly the most sophisticated task. On the contrary, it is quite a simple and straightforward method.

However, the one thing that remains consistent is water replacement. Since clean water is the essence of your betta tank, it is imperative that you change it at regular intervals.

Let us look at why it is vital to frequently change your betta tank water and how to do it properly.

Why is it important to change your betta tank water?

The main reason is that your aquarium water develops harmful chemicals like ammonia and chlorine over time. These compounds (as you might have guessed) are harmful to your betta fish.

Besides, they also disrupt the ideal pH value of your betta tank. Generally, the recommended pH value for safe aquarium water should lie between 6.5 and 8.2.

As a result, if you do not replace your betta tank’s water from time to time, you may be jeopardizing your aquatic companion’s health.

Whenever you feed your betta, some of it gets accumulated on the surface, which later decays. In addition to that, your betta fish also release urine and feces into the water.

The accumulation of all these waste particles deteriorates the quality of your aquarium water.

Contrary to what many people believe, the filtration system isn’t enough to keep the betta tank running clean and smooth. In contrast, replacing water on a routine basis is the best way to ensure the safest atmosphere for your aquarium fish.

How often should you change your betta fish’s water?

The frequency of changing your betta tank water depends on numerous factors. The two most common factors include the size of the tank and the number of bettas.

Large tanks with a betta fish population may require sporadic maintenance. Whereas a smaller and packed aquarium may need more frequent attention. 

It is also critical to understand that people do not just empty the tank and replace the entire water volume at once. Such an abrupt change in the quality of the tank water can stress out your bettas.

It is, therefore, a more practical approach to change only a small volume of water at once. Here are some standard rules of thumb for changing the water in an aquarium based on different conditions.

  • The ideal method for a sparsely betta fish tank is to replace about 10-15% water every 2-4 weeks, check out this post for more information on
  • For a heavily betta fish tank, it is recommended to change about 20% of the water on a weekly basis.
  • For an average inhabited aquarium, change around 10-15% water each week. 

In addition to just replacing the water in the tank, you should also make sure to check its new temperature and pH level. After all, that is the entire point of changing the water in the first place.  

Best tips for changing the water in your betta fish tank

  • Remember to vacuum the substrate when you’re changing the water in the betta tank. This is crucial because the majority of dirt and debris lie in this area. You can buy some of the best aquarium gravel cleaners in your local aquarium stores or several e-commerce sites.
  • If your betta tank size is small, you can opt for different cleaning equipment like a cup to scoop out the water. This is more of a precautionary measure as gravel vacuum cleaners may suck out excess water at once. 
  • Let the water sit for a day before you pour it into the tank. This will provide enough time for dissolved gases to dissipate. What this does is that it will allow the water to come back to its normal room temperature, ideal for your fishes.
  • Do not forget to clean the water filter. But make sure to just give it a light rinse. If you conduct a full-on cleaning process for the filter, it may disrupt the water’s bacteria balance. Such an abrupt change in water quality is never good for your bettas.
  • It is also not suitable to clean the filter and the gravel the same day. Doing that will raise a lot of unwanted complications—both the gravel and the filter harbor “good” bacteria. Cleaning them simultaneously will disturb the water nutrient balance by a substantial degree.

Thus, avoid cleaning both the areas at once if you do not want to stress out your fish.