The importance of the pH level in an aquarium can hardly be overestimated, as it directly influences the quality of water and the life and well-being of the tank inhabitants. Both too low and too high pH levels are harmful to fish. To some extent, the problem of a low pH can be solved by a regular tank cleaning. However, if you want to get a steady long-term effect, you should create the right environment by adding useful items to the aquarium and using bicarbonates. Don’t forget to measure the pH level with special testers to keep sure you are moving in the right direction.

Table of Contents:

Measuring the pH Level
Raising the pH with Bicarbonates
How to Raise the pH Naturally

Measuring the pH Level

Before you do anything to change the pH level in your aquarium, you need to make clear for yourself what it is and why you need it. Also, it’s important to know how to test the pH in the fish tank and what tools suit best for this purpose.

What Is pH and Why It Is Important

In simple terms, pH refers to the density and activity of hydrogen ions in the liquid. A low pH means the liquid is acidic, while a high pH is typical for alkaline liquids. Distilled water has the a pH level of 5.4-6.6. However, most aquarium fish feel good when the pH of the water is 7 or higher.

The pH of aquarium water can be changed in different ways. Firstly, you may dilute the water from time to time in order to change the concentration of hydrogen ions. Secondly, you may add carbonate, bicarbonate or hydroxide to the fish tank. Thirdly, you can use coral substrate or rocks – this is how to raise pH in an aquarium naturally.

Beware that higher pH levels are often accompanied by an increased concentration of ammonia, which, in turn, increases the toxicity. That is why don’t forget to check the water for the content of ammonia before raising its pH level.

Find out What pH Level You Need

You always need to consider that different species of fish feel comfortable at different pH levels. So, the first thing you should do is to look for information about the species you have. Check aquaristics guides or consult specialists at the local pet store. Tons of useful information can be found in specialized communities and forums on the Web. Approximate recommended figures for various types of fish are as follows:

  • tropical fish – pH 7 through 7.8;
  • saltwater fish – pH 8 through 8.3;
  • freshwater fish – pH around 7.0.

For the majority of aquarium habitats, the pH level of lower than 7.0 is harmful. Some species can survive in a slightly more acidic environment if there a lot of natural plants around. However, a general rule of thumb is to avoid this.

pH test kit

Testing the Water for pH

Testing the water is mandatory, as you need to know how much you should raise pH in the fish tank. The conventional method of testing is using inexpensive chemical meters. A chemical testing kit includes special testing solution, a glass tube, and a color card. A digital tester is a more advanced and easier-to-use option. The only possible trouble with it is the need for its regular calibration. Once calibrated, it provides precise results fairly quickly.

Raising the pH with Bicarbonates

Adding bicarbonates is an easy way to increase the pH level in an aquarium. Commonly, bicarbonates come in the form of a buffer, which can be bought in specialized aquarium shops. In terms of its chemical composition, a buffer is a mixture of bicarbonate and sodium carbonate. Keep in mind that it’s recommended to raise the pH with bicarbonates gradually. Here is a general instruction.

  • Prepare the solution first. Take 0.5 tsp of buffer per 5 gallons of water.
  • Mix it up with water carefully.
  • Pour the solution into the tank. Try to pour it into the water flow in order to distribute it evenly.
  • A filer and an aerator must be on.

In one or two days, test the pH once again. If the desired level is not reached yet, repeat the procedure. If you fail to raise alkalinity with bicarbonates, test the water for carbon dioxide (CO2). If the concentration of carbon dioxide is too high, the pH can stay low despite the normal alkalinity. That’s why it’s important to check the water alkalinity as well. Maybe, it makes sense to change the water.

How to Raise the pH Naturally

How to raise pH naturally

If you are looking for how to raise pH in an aquarium in a natural way, you can modify the environment by adding some items and cleaning out the tank.

Add Some Rocks and Minerals

It’s a good idea to change the substrate using certain minerals. They are inexpensive and you can purchase them at any pet store. The most popular of them are limestone, corals, and Texas holey rock. The thickness of the substrate layer must be around one inch. Don’t forget to remove your aquarium habitats before adding the rocks, as they produce a lot of dust. Keep in mind that the effect is not immediate: you may see positive changes in the pH level in a week or so.

Seashells as a Natural Source of Carbonates

Seashells serve as sources of carbonates, which means they can gradually raise pH in a fish tank. It’s recommended to add two shells per gallon. You should use only clean non-painted natural seashells for aquariums. Before placing them into the water, rinse each shell thoroughly. Fish and other aquarium habitats can stay in place – there’s no need to remove them. Keep in mind that their action is rather slow, so you can expect visible results approximately in a week.

Take away Driftwood

Natural driftwood can look beautiful, and some people use them to decorate their aquariums. Meanwhile, it produces acids (namely, tannins), which tend to change the chemical composition of water to the softer end. This, in turn, leads to altering the pH balance. Sometimes, all you need to do is to remove driftwood. There’s no need to remove the aquarium habitats or clean the tank – just take it away and test the water for the pH in a week.

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