How Often To Change Fish Water Tank

Contrary to popular belief, when it comes to fish they actually require regular maintenance, even though it is widely believed that you can just leave them to get on with it.

It is really important to note that the type of water in which your fish live can affect their health.

This means that you will need to change your fish tank water on a regular basis – but still not overdo it.

This will ensure that your fish stay happy and healthy.

Saying that, it all depends on what kind of fish you have.

For example, if you have an aquarium with saltwater fish, it’s best to keep the water fresh by changing it at least twice a week.

On the other hand, freshwater tanks need less frequent changes because they are usually fed only once per day.

So, without further ado, let us take a look at why it is important to change the water in the fish tank. 

Why Do You Need To Change The Fish Tank Water?

Water changes are important because it removes excess waste from the tank, and it can only be done by changing the water.

Other chemicals may break down over time, but they accumulate much more quickly than the breakdown process occurs.

Water changes are like spring cleaning for an aquarium.

Opening the windows, beating the carpets, dusting the furniture…together, the entire atmosphere of the house changes and you feel much happier as a result.

Your fish become lethargic as toxins accumulate, making water changes essential for proper health.

How Much Water Should You Change?

The frequency of the water change all depends on the size of the fish tank and how many fish are in there.

So, basically it all depends on the accumulation of waste in the tank and the rate it builds up.

If you have a heavier stocked small fish tank, then the rate at which you change the water will be more frequent compared to a big fish tank with fewer fish in it.

However, there are so many other factors which we shall look at below.

Water changes should be something you schedule in as part of your fish regular maintenance.

Whilst you should be following the rules of changing the water compared to how much waste is generated, there are some other rules of thumb to live by.

You should be changing the water at least once a week, though you can do it every two weeks if once a week is not ideal for you – though if you own fish, their health must be a factor with when you schedule in their maintenance. 

You can change around 10 to 15% of the water each week, or 20 to 25% if you are doing it every two weeks.

Now if you have quite a heavy stocked tank, then you will want to change 25% of the water weekly. 

If you have a light fish tank – really light – then you can get away with changing the water every two to four weeks. 

Factors Of Changing A Fish Water Tank

The frequency of water changes depends on several factors such as:

• Size of the tank
• Type of fish
• Amount of food available
• Age of the fish
• Health of the fish
• Temperature of the water

Helpful Guidelines Of Changing Fish Water Tank

If you’re not sure how often to change your fish tank water, here are some guidelines:

• Freshwater tanks need to be changed more frequently than saltwater ones.
• If your fish has been sick recently, you’ll want to change its water sooner rather than later.
• A small aquarium needs to be changed about once per week.
• Medium-sized aquariums need to be changed about once every 2 weeks.
• Larger aquariums need to be changed every 4 weeks.
• Tanks with very large numbers of fish (such as schools) need to be checked about once a month.
• When you first set up your aquarium, you’ll want to check the water daily. Once a week is fine after that.
• Twice a week is recommended if you notice any signs of algae or cloudy water.
• Three times a week is recommended if there is no sign of algae, but the water appears murky.
• Four times a week is recommended when the water looks crystal clear.
• You can use tap water instead of bottled water. However, make sure that you don’t add chlorine or chloramine to your tap water. These chemicals can harm your fish.
• Always test the pH level before adding new water to your tank.
• Make sure that you remove all air bubbles from the water before adding it to your aquarium.
• Never leave your fish unattended while the water is being changed.
• Don’t let your fish swim around in the tank during this process.
• Do not allow them access to the filter until it has been cleaned.
• Be careful not to overfeed your fish. This will cause toxins to build up in the tank. 
• Avoid using too much water.
• Keep an eye out for any dead fish floating in the water.
• Check the temperature of your water regularly.
• If you see any signs of disease, call your local veterinarian immediately.

Is It Possible To Change The Water In A Fish Tank Too Much?

There is not an expected amount or time you need to change the water in your fish tank, because as we have stated, it all depends on many factors.

Changing the water in your fish tank too much may cause an excessive amount of stress to your fish.

Some levels of uniformity are important, so do not change the water too often. 

It is recommended you prepare your water before making any changes to ensure the settings and parameters are similar to what you’ve got in the fish tank, especially the overall temperature setting and pH levels.

Having stated that, there will be times when you may have to do a 90-95% water change in the fish tank.

For instance, if there’s a significant snail problem or algae issue.

Also if there is widespread infection.

Water changes should be done slowly and carefully.

You also need to make sure that the water is completely changed before adding new fish or plants.

Also, consider taking precautions when dealing with water changes.

Don’t use a full water change unless you really need to.

A nitrogen cycle is an important part of the aquarium environment. 

Partial water change should be done once per week.

Water changes should be done every two weeks or even less often.

You should stagger them, doing one every few days.

Be sure to match the temperatures, pH, salinity, and GHS to what your fish are used to. 

Final Words

How often you should change the water of your fish tank water can be confusing, especially if you are new to owning fish.

There are a lot of different factors when it comes to the frequency of changing the water, such as whether you own a large aquarium, how many fish you have, and also the type of fish.

So long as you stick to the guidelines, you will be able to understand how often you should be changing the water without affecting the health of your fish.

After all, changing the water is an important maintenance duty to schedule in, so it should not be avoided entirely if you want your fish to survive.