Connect with us


Is Apple Cider Vinegar Safe for Fish?



Is Apple Cider Vinegar safe for Fishes

Yes, you can use apple cider vinegar, but there are a few things you should know about the vinegar before you use.

It happens more often than most people would like – the dirty fish tank. As much as it is a nuisance and requires a lot of effort, it needs to be cleaned regularly. Fish need a clean environment to survive and is something that needs to be done for them. 

Usually cleaning a fish tank requires a person to use chemicals, that if used incorrectly could kill your fish.

That is definitely something you want to avoid. So, what do you do? Are there perhaps any natural ingredients that could be used instead of chemicals to clean fish tanks?

The answer is yes! You can actually use apple cider vinegar in this case. 

There are some things that you should be aware of before you do so though. Just like with using chemicals, if you spill too much inside the tank or don’t rinse it out properly, you run the risk of changing the PH level of the water. Which could very easily kill your fish. 

Another factor to consider is the vinegar itself.

You should try and avoid using any other type of vinegar besides raw, organic apple cider vinegar. It is a naturally fermented vinegar that has a large number of good probiotics in it. These can be more beneficial than what other vinegar’s contain. You especially want to avoid any vinegar’s that are flavored. 

As you are probably aware, it is considered good practice to rather move fish to a separate tank before cleaning the dirty tank. If you do this, you can take the cider vinegar as is and clean the tank out. You can add it to a cloth directly and then apply some elbow grease to clean the tank. A quick rinse and the tank will be ready. 

If you are not able to move the fish and the tank isn’t overly dirty, you can also dilute the vinegar with a good amount of water before carefully cleaning the tank sides. If diluted properly, the vinegar won’t affect the fish. 

What is Vinegar and What types do you get?

And which vinegar is used for cleaning fish tanks and which should you not use? 

Simply put, vinegar is a weak solution of acetic acid with a concentration between 5%-8%. The way the acetic acid is made is not difficult to understand.

The natural sugars in a liquid are converted to ethanol by various types of yeast.

Ethanol is an alcohol that is further broken down into acetic acid by special bacteria. 

Now you might think that since vinegar is all made in the same way, they must all be the same thing. That is not true.

Each vinegar has an extremely different makeup due to the different types of bacteria present. Some bacteria offer better qualities than others.

This is the case with apple cider vinegar, due to the substances found in the apple cider, the bacteria found there offer great health benefits overall. 

Different types of vinegar’s available and their use in cleaning fish tanks.

What impact do their acidity levels have on water quality?

There are many types of vinegar available today. As we’ve explained how they are made, we will quickly list the common types found in most supermarkets:

  • Apple cider 
  • Red wine 
  • White wine
  • Champagne
  • White spirit vinegar
  • Malt vinegar
  • Brown spirit vinegar
  • Grape vinegar
  • Balsamic vinegar

So, as you can see, there is a huge variety of vinegar’s that can be found in most supermarkets. And this can give one the impression that they can all be used for cleaning the tank. That is however, not true.

The higher the acid level in the vinegar, the more it will affect the PH level of the water in the fish tank. Another large factor, is the amount of vinegar than one can use in cleaning the fish tank. A stronger vinegar would need to be more diluted than other types if used.

Ideally, one should only use apple cider vinegar or white spirit vinegar in cleaning the fish tank. Some people suggest that a ratio of 1:3 of vinegar to water is the strongest that you can use without causing harm to the fish.

The reason why we suggest the two vinegars above and not the others is due to how pure they usually are.

Cider and spirit vinegars normally don’t have any additives in them and they are filtered very well. This lessens the likelihood of something unwanted affecting the fish.

Will Vinegar Kill Your Fish?

The very simple answer is – yes and no. It is both yes and no because it will depend on you.

By now, with your fish, you should know that some varieties of fish are a lot more sensitive than others. But, regardless of that, if you use too much vinegar in your cleaning solutions, you will definitely kill your fish. There is no doubt about that.

In the previous section we discussed what varieties of vinegar can easily be sourced and which ones should be used in the cleaning of your fish tank.

Cider and spirit vinegars have a similar acidity and purity level – making them ideal for cleaning. If used correctly, the fish will be fine.  

How much Vinegar should one use while cleaning their fish tank?

This will depend on two things – the size of the tank and whether the fish are going to be inside it when cleaning. It should be obvious to everyone that every fish tank will differ in size, but that doesn’t make it impossible in creating a winning formula.

Whatever the size of your tank, a ratio of 1:3 with vinegar to water should be more than sufficient for your needs. If you use this ration (or less), you can actually apply the solution while the fish are in the tank. If you go higher than that, you run the risk of killing the fish.

However, if you can remove the fish for cleaning the tank, you can use a ratio of 1:1. You just then have to be very sure to rinse out the tank very well so that the residue from the vinegar won’t affect the fish.

If you really have stubborn stains that won’t come out with such a concentrated solution, it has been advised that you use some table salt with the vinegar.

That will take care of any stains. But, be sure to rinse the tank out properly – the salt can be just as deadly as the vinegar.

How to clean a fish tank using vinegar?

Thankfully this is not a difficult job to do. It may even be easier than you previously thought. There are two ways of cleaning a fish tank with vinegar. You will either have the fish in or out the tank; once that is decided, the process is the same thereafter.

The fish stay in:

  • The first thing to do in this process is prepare your vinegar solution.
  • Take a clean bowl and prepare a solution using apple cider vinegar with 1 part vinegar to three parts water.
  • Take a clean cloth or sponge that has never been used before (this is vital) and soak in the solution.
  • When that has been soaked properly, take the cloth or sponge and gently clean the sides of the fish tank. Take great care to not hurt any fish while cleaning.
  • Soak the cloth again as needed and carry on rubbing until the tank is cleaned.

The fish get taken out:

  • Depending on the severity of the dirt in the tank, you might want to increase the strength of the solution to 1:1. If it is not needed, keep at the same strength as the first process.
  • Be sure to use a clean cloth again and you can scrub as hard as you need to without worrying about hurting the fish.
  • When the tank has been cleaned sufficiently, be sure to rinse it out with clean water a few times to get rid of any residue.

The only reason you would use the second method is if the fish are very sensitive or the dirt is difficult to get rid of with the weaker solution. Other than that, the first method is great for cleaning maintenance. This is all that you need to do when using vinegar to clean the tank.  


There are a great variety of vinegar’s that can be easily sourced, but they don’t all do the same job. Our suggestion is to use apple cider vinegar as it is more natural and less harmful to fish in general. We have shown you how it is made and why it can be useful to use instead of chemicals.

We have also shed some light on the proper processes to use in cleaning a fish tank – whether the fish are in or out. And we have shown you when you would need to take them out. Apple cider vinegar is an incredible ingredient to use in cleaning fish tanks that is cheap, easy and effective. Why not give it a go? It may surprise you!   

Click to comment

Leave a Reply

Affiliate Disclaimer:

Our website contains affiliate links, which means we may earn a commission if you click on or make a purchase through these links. This comes at no additional cost to you. We only recommend products and services that we believe will provide value to our readers and visitors. These affiliate relationships help support and maintain our website, allowing us to continue providing valuable content. Your support is greatly appreciated, and we thank you for trusting our recommendations. If you have any questions or concerns, please don’t hesitate to contact us.”