What Causes Low pH in Aquariums? + 3 Symptoms Of Low pH

Last Updated on October 21, 2022 by Griselda M.

What causes low pH in aquariums? Click and learn how to solve this difficulty that plagues many aquarium lovers.

To give your aquatic inhabitants a healthier and happier life, the water in their tank needs to have a pH level that is as close as possible to neutral. Wondering why? Namely, too high or too low a pH level impairs water quality and significantly affects the health of the pet.

So, what causes low pH in aquariums? Stay with us to find out.

What is pH?

Simply put, pH is a measurement of the concentration of hydrogen ions in a water-based solution. A lower pH means there are more hydrogen ions in the liquid, and on the other hand, a higher pH indicates fewer hydrogen ions in the liquid.

The pH tells us about the acidity or alkalinity of a liquid. On the pH scale, 7 denotes neutral, so anything that has a pH below 7 is an acid, and anything with a pH above 7 is an alkali or base.

Symptoms Of Low pH in Fish Tank

The following examples are some of the symptoms that can occur as a result of too low a pH level. They are also listed in chronological order, from the earliest signs onwards.

1. Death

The primary symptom that indicates that something is wrong is the death of the new fish, while the old fish remains alive and seemingly healthy. Why does it happen? Namely, old fish are accustomed to the current state of the water (accumulation of certain chemical or bacterial levels), while new fish, unlike it, is not. This is why your new aquatic pets can die.

2. Algae Growth

If you notice the spread of green algae in your aquarium tank, this is the first sign that the pH level is too low. They most often occur due to increased amounts of available nutrients and light.

They are pretty ugly to see, pollute the water, and make your fish vulnerable to disease.

3. Sludge & Dirt Build Up On The Bottom Of The Aquarium Tank

Sludge most often occurs as a result of uneaten fish food that has accumulated at the bottom of the fish tank. This food breaks down in an oxygen-poor environment and turns into something that looks like mud or sludge.

The presence of sludge is not desirable as it prevents the flow of water, clogs the filter, and releases an unpleasant odor into the tank. After all, it stresses your aquatic pets.

symptoms of low ph in fish tank

What Causes Low Ph in Aquariums

Lack of calcium & alkalinity

Calcium and alkalinity are essential for the formation of buffers and a healthy pH level. If they are deficient, it will affect the pH of your aquarium water.

Faulty filtration system

Only a quality and powerful filter can keep your tank in good condition. Otherwise, your tank will have a buildup of fish waste at the bottom, as well as algae on its glass walls. Therefore, try to clean the filters regularly.

Lack of plants

Since plants remove toxins from water, they help stabilize the pH of your aquarium water. However, we can’t insert just any plant and expect it to work wonders. Also, not all types of plants absorb harmful substances from water. Therefore, it would be good to ask for information at the local fish store.

Crowded aquarium

The bigger the crowd, the more food you will need to feed these fish daily. This will eventually result in more waste at the bottom of your fish tank. This waste is usually a source of ammonia and nitrite. In addition, a larger crowd affects the pH level of the water, i.e., lowers it.

How To Raise pH in Saltwater Aquarium

Lime water and some two-part pH additives can significantly raise the pH level without excessively increasing the alkalinity. Another way is to reduce the CO2 content. The best way to do this is to have a refuge where you can grow macroalgae, which helps reduce CO2 levels from the aquarium.

Did you know that you can add baking soda to your aquarium tank? You can increase the pH in the aquarium by using about 1 teaspoon of baking soda for every 5 gallons of water. Furthermore, adding shells or rocks can do wonders for your tank’s pH. If you don’t like their appearance, you can put them in hard-to-spot places or a filter.

Find more information about Adding Baking Soda To An Aquarium

How To Raise pH in Freshwater Aquarium

Almost the same is true for freshwater aquariums.

However, before taking any step, it is necessary to test the tap water, if you use it. The pH of tap water varies throughout the country so it may be slightly lower in your country.

If the pH of tap water is significantly higher than the pH of the aquarium, it is necessary to test for ammonia, nitrites, and nitrates. Also, remember, aquarium decorations can lower your pH level as well.

Let’s not forget, pet shops also sell chemicals specifically designed to raise the pH of aquarium water. You can also get cichlid salts that dissolve and raise the pH and alkalinity of the aquarium water.

How To Test Aquarium Water?

It’s very simple, you can do it with an inexpensive electronic test kit. The most important thing is to choose the one that best suits your needs. Some require you to use tiny drops of liquid, while others require you to completely immerse the tester in the water of your tank.

In Conclusion

If the pH drops too low, you will notice that your fish starts to get sick or in an even worse die. The best way to prevent this is to monitor the pH level of your aquarium and test the water regularly. This will help keep any issues from getting out of hand.

We hope you found this article on “What Causes Low Ph In Aquariums” useful. If you have any tips and tricks related to this topic, let us know in the section below.

Read more about The Best Freshwater Aquarium Test Kit