How to Lower PH in Aquarium with Vinegar

How to Lower PH in Aquarium with Vinegar. Water is the most important part of your aquarium that can directly impact on your fish. But most of the fish owner is unconscious about this major part of the aquarium, and they always try to avoid this crucial thing.

If your tank water has a lower or higher PH which indicates how much alkalinity and acidic your water; can be very lethal to your fish and may cause of fast death.

On the fish health, It is considered that the neutral ph level of 7 is ideal for tropical fish, although many fish can do well in the ph level of 6.8 to 7.6

The ph scale is below 7.0 means the water has more acidity, and it is more acidic.

On the other hand, when ph level of up to 8, it means the water has less amount of acidity and becomes more alkalinity.

To lower the ph, there are many alternatives available and one of them it’s using vinegar to get instant result.

However, when you use vinegar to lower the PH from the fish tank, it’s important to know how vinegar affects on your aquarium water and fish health.

In this post, we will go through identifying how to lower the PH in an aquarium, what types of effect can have on your fish and some alternative way to lower the PH from water.

What Causes High PH in Aquarium

There are many reasons why a fish tank has high PH in the water. Such as,

  • Hard Water
  • Wrong types of substrate
  • Failure filtration system
  • Medications
  • High mineral traces
  • Lack of carbon dioxide
  • Waste and debris
  • Using tap water
  • Chemical
  • Inappropriate plants

How to Lower PH in an Aquarium with Vinegar

It is possible to lower PH from water in the aquarium when you can do it properly; otherwise, it might be dangerous to your pet fish.

When you use vinegar to decreases the PH, it is important to know thoroughly about the water chemistry and the effect of vinegar on the fish tank.

lower ph in aquarium with vinegar

If your aquarium doesn’t have any live plants, it is not recommended to use vinegar as they increase the carbon dioxide, which is also harmful to your fish.

In the fish tank, when acetic acid (vinegar) combines with oxygen, then it releases bio carbonate, which helps to reduce PH in the aquarium. Thus the vinegar work to lower ph.

Here is the step by step process to lower ph in the aquarium with vinegar:

1. Test the PH level of water

Test the PH level of water in the aquarium to determined the present balance.

Before beginning the task, it is the best idea to check the present ph level of the water so that we can measure the progress.

2. Add diluted white vinegar

Add a small amount of diluted white vinegar into the water. It is ideal to use 1 ml (max) of vinegar in the per gallon of water.

3. Measure the water

Measure the water and add vinegar gradually if needed to ensure there is no chance to overuse

4. Test PH again

Test PH again carefully before adding more vinegar

5. You are done!

Make sure it is done what you except the level.

Note: Lower ph with diluted white vinegar is not a stable and permanent solution. Add vinegar continuously may have a stable ph level, but it is the riskiest process.

If anyhow you add more vinegar than what it’s needed, can make your tank water lethal toxic.

What is the Normal PH in the Fish Tank

In the fish tank, every species of fish need different types of PH level, although the PH level is not static.

How would be the PH level in the fish tank, actually depends on the day and weather and can change the balance within the few hours.

Normally Freshwater fish in the aquarium requires less alkaline, and they do well in the range of ph 5.5 – 7.5.

On the other hand, saltwater fish requires a pretty high level of alkaline than a freshwater fish. They need above the 8 of PH levels to live well in an aquarium.

There are some common freshwater fish and the PH levels that they require in the aquarium:


The preferable ph level of goldfish is around 7.5

Neon tetra

Neo tetra can live well around the 6.0 level of ph, which is preferable for them.

Zebra Danio

They require 6.5 to 7.0 ph


Like Zebra Danio, they also need to 6.5 to 7.0 ph to live in the aquarium.

How Often to Test Aquarium PH

You should test the PH once a month, but it is preferable to test once within two weeks so that you can take action before going anything wrong with the water.

You can record the test report for future reference.

Keep in mind what would be the ph report is mainly depend on the time of the day, testing at a different time, most probably the result shows the different value even though there’s nothing is wrong.

So, the test should be at the same time of the day and the preferable time is in the afternoon.

Besides this, you should test the ph

  • When any fish get ill or die
  • When the tank is treated by the medication
  • Before using medication
  • After using medication
  • When using any chemical
  • Before purchasing new fish

Whenever you discover the tank fish got ill or die, the ph test must be done instantly. Even, if you need to treat your aquarium by the medication, it is ideal for testing before and after using the medication.

It is also ideal for testing the PH when you buy the new fish. When buying the fish, you should check the shop water PH so that you can compare between your aquarium water and the shop water to ensure there is no higher PH difference. (The difference between 0.2 slightly above or below is acceptable)

How much vinegar is needed to reduce PH

The safe amount of vinegar to reduce ph depends on your aquarium size and types of fish. It is normally preferable to use 1 ML of diluted white vinegar for each gallon of water that is safer for your fish, and this amount doesn’t make any danger.

But adding more vinegar than is required might make the unsafe situation for your fish. Even it can cause abnormal fish death.


Producing too much carbon dioxide behind the increase of oxygen can hamper your fish to lead them a normal life.

If you use to reduce diluted white vinegar, check the present water condition before and after adding the vinegar.

To do the task successfully, make sure you are adding vinegar by a small amount of part to ensure there is no chance to add more vinegar that can make your fish difficulties.

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