How To Raise pH in Aquarium Naturally | Learn The Best Ways

How To Raise pH In Aquarium Without Chemicals Today?

Being able to increase the pH of your aquarium is an important skill one must have. It can come in handy in a few other ways.

Perhaps you are attempting to create your water conditions good before adding your first fish? Or might you’ve seen a pH level drop in your established aquarium and you require to correct it?

If the pH level is well controlled, your fish will be happy in your fish tank for years. If a mistake is made by you, then you may lose your fish early on.

The pH level generally remains stable, but if any problems occur, you have to be able to fix the issue before they affect your fish. This blog article will ensure to support you with that.

Here in this article, we shall try to explain so many ways to help you raise the pH of your aquarium. Some other important aspects will also be covered, such as how to test pH, what pH is, and what the natural pH should be.

What Is pH?

In any water-based solution, the value of pH indicates the concentration of hydrogen ions. It tells you how alkaline or acidic the water in the aquarium is.

In the year 1909, a Danish biochemist named Søren Peter Lauritz Sørensen explained the following equation that has been used to calculate pH level ever since (although there are little variations): pH=-log[H+]

This is complicated and small, but luckily there is no need to remember it. You can simply purchase a testing kit from your nearest pet store that can calculate the aquarium’s pH for you. So many pet stores even provide to test your aquarium water for free, if you bring in a sample with you.

You have to bear in mind the pH scale, as this is what you can refer to when the pH has been ascertained.

The scale usually spans from 0 to 14. If the pH level of your aquarium water is less than 7, it is acidic. If the pH level is more than 7, then it’s assumed as alkaline. An exactly 7 pH is termed as being “neutral”.

Your values would be negative if the liquid is highly acidic. In the same way, the values may exceed 14 if the water is highly alkaline. You won’t encounter these situations while fishkeeping though.

A few liquids do not possess a pH, such as gasoline or vegetable oil. To have a pH value the liquid must contain water.

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Factors That Influence The pH In Your Aquarium

Here you will know how to lower the ph in a fish tank and how to raise the pH in an aquarium-

  1. Before and after water changes, the level of pH can be different, especially if the pH of the aquarium and the aquarium water itself vary
  2. Reduced aeration will lower the pH level
  3. Driftwood softens the water and therefore the pH becomes lower
  4. The pH can be lowered by adding CO2
  5. The high amount of nitrates may cause the pH to drop
  6. Waste and pollutants in the water will lower the pH level
  7. Any type of crushed coral (ornaments or substrate) will increase the level of pH
  8. Hard water also causes higher pH levels
  9. Using a water purifier may lower the pH levels ( it is good with hard water)
  10. Generally, soft water is low in pH
  11. RO water contains a pH of 6 or lower than that
  12. Overstocked fish tanks can be low in pH

The main factor is stability. Always keep in mind that fish may adapt to a pH that is a little off their most well-liked preference. It’s the fluctuations that cause fatalities and stress.

During the daytime, the pH will vary. It should be tested in the morning or evening time. Always make sure that the test kit is not expired.

Why Is pH Important?

Knowing pH is important for many everyday uses. Preservation of food, Cooking, medicine, and water purification are only a few examples. This is assumed to be crucial in the fishkeeping world.

In the same manner, which you will utilize an aquarium heater to regulate the temperature of the tank water, you must control the CO2 and pH. These all are required to do with the importance and preferences of your fish.

One species may bring a different pH range than others. These all are typically based on the true natural habitat of populations that are found in the wild environment.

A lot of species are particularly bred to the point where they have various preferences for their natural counterparts.

It can be fatal for your fish if the level of pH in your tank is not perfect. A lower level of pH may effectively burn their skin. A very poor level of pH may lead to health issues and is poisonous.

This is the same for other parameters. For example, a fish’s immune system can be weakened by a temperature drop.

A little change in the pH level may also help pathogens to thrive. This creates disease, another issue for you to deal with.

Every week test the conditions of the water in your fish tank. This will help you to spot changes in pH quickly, to decrease the probability of fatalities.

How To Check The pH Of Your Aquarium Effectively

No complicated science or math is required to do, you only require to purchase a water pH testing kit.

Most of the stores sell these, however, you may find this item online if you don’t have any. The price may differ depending on the type and brand, however, many of them are inexpensive.

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Some pet stores will test your aquarium water for free if you don’t want to pay any amount of money. You have to bring the water in a sample container though. This may take some time and makes it tough to test your tank water every week. Therefore it isn’t a long-term solution.

Digital pH testers are the most expensive, but again they are the most convenient too. You only have to dip the endpoint of the pH testers in the tank water and the value of pH will show on its digital display.

Manual testing kits are much cheaper and more commonly used.

You can easily purchase pH test strips that are made from dyed litmus paper. Dipping this type of testing kit in tank water can cause them to change their color. To calculate the pH, you just have to compare this color with the given color-coded chart.

Most of the pH test strips can check so many parameters in one dip, such as carbonates, nitrites, nitrates, and water hardness.

Some manual pH test kits need you to mix a sample of the tank water in a chemical solution. It changes the color but it is not more convenient.

Once you run out of chemical solutions or strips, you will have to purchase more. A digital pH tester will perform indefinitely if it does not malfunction. Every process is effective. The one you select can likely depend on its price.

Fish Tank pH Level Chart:

How To Raise pH in Aquarium Naturally

What pH Should Your Aquarium Be?

Proper pH for Freshwater Aquarium: The pH of your tank will depend on the species of fish that you keep. At the time designing the right aquarium for your fish, your main task is to rebuild their natural habitat as well as you can (including the pH).

It’s convenient to search out the preferences of the fish if you’re not sure. We recommend an ideal pH on our different species’ care guides.

It will also be mentioned in fishkeeping books or you could ask the staff in pet stores.

You may see that all types of aquariums tend to possess different pH. Tropical fish tank pH is typically between 6 and 7.5. On the other hand, the marine tanks are in the range of 7.5 to 8.5, with reef aquariums being positioned at the higher end of this range.

Although there are a lot of exceptions to this, that is why it is the safest mode to check the specific requirements of your fish in the tank.

One perfect example is African Cichlids like more alkaline water conditions compared to most tropical fish. Some of them are kept at a pH level of up to 8.5.

Don’t forget to check that the pH is suitable for any other life in your fish tank, such as invertebrates or plants.

What Can Affect The pH Of Your Aquarium?

Sometimes pH is beyond your control. It may get higher or lower due to a variety of reasons. Be cautious of the following conditions and fix the level of pH to the normal situation if you see any change.

When you set up a new tank, you must cycle it to grow beneficial bacteria populations. This method is known as the nitrogen cycle. It can make your aquarium more acidic.

During the period of a fishless cycle (which is recommended), your fish are not added to the tank until the nitrogen cycle is complete, so it shouldn’t be an issue.

This cycle could be triggered a second time unintentionally though, then the changing pH level could badly affect your fish.

Tannic acid can also lower pH. This is a consequence of placing tannins associated with some decorations, like peat moss and bogwood.

While adding these types of things to your aquarium always be careful. If you are prepared for a drop in pH, then only do so. Placing tannins could be a good process for decreasing your pH level if it ever gets very high.

For the purpose of human drinking, your tap water is treated by using a variety of chemicals to make it safe and pure. These chemicals influence the water’s pH too.

The chemicals used can vary in different locations, so if you change the source of your water (perhaps by moving to a new house), your aquarium’s pH could be affected.

How To Raise pH In Aquarium Naturally

What causes ph to rise in the aquarium? A drop in pH can be a big problem, but don’t worry, there are many solutions for you to try and raise the pH of your aquarium. Read the following ideas thoroughly and choose which one would be the best option for your own situation.

Aerating The Aquarium Water

Increase the concentration of dissolved oxygen in your tank water to raise the pH level. The reason behind this is, you would be lowering the amount of concentration of carbon dioxide.

Carbon dioxide produces carbonic acid and Carbon dioxide is acidic when dissolved in water. A high amount of concentration of carbonic acid may reduce the pH significantly.

There are so many ways to oxygenate your tank water. The easiest way is to introduce the aquarium filter outlet above the surface of the tank water. This will disturb the water, which aids the movement of oxygen from the air.

With the help of air/water pumps, a stronger effect can be generated. The increasing aquarium currents, also help air to move into the water of fish tanks. Ensure that your aquarium fish can resist strong water currents though.

If you change the water regularly, it will keep oxygen levels high too.

Water Changes

The pH of an aquarium can gradually become lower as pollutants build up. There are so many ways, where pollutants are released, such as decaying food or fish waste.

Removing these water pollutants can assist to bring the pH back to its actual level.

Remove 20% of the aquarium water in your tank every 2 or 3 weeks, and alter it with pure tap water (after treating the water with de-chlorinator).

Regularly changing small amounts of aquarium water is safer than altering large amounts less often, because this might shock your fish.

As general care and maintenance of your aquarium, you must be performing water changes anyway and in any situation.

Baking Soda and Chemicals:

How to lower the pH in a fish tank with baking soda?

Baking soda is another natural and easy way for you to raise the level of pH of your aquarium water.

Baking soda will raise the pH, which is usually found in the kitchen. Adding some amount will generate quick results. The pH will fall back to its original value if you do not do this regularly.

You should not add a high volume of baking soda in one goes, if the pH level rises too high or too quickly, your aquarium fish may suffer a lot.

Sometimes, people add more than what is needed. The consequence is that you will end up with an aquarium with a high spike in pH levels, thus killing the fish in your fish tank. Also, You will have to add it more often, using baking soda is not just a one-time thing, and you are done for life.

The general rule of thumb: You should add a teaspoon of baking soda per 5 gallons, but the slower and steady you go, the much safer your fish will be.

There are chemicals that you can buy which are intended to work in a similar way to baking soda. It could be difficult to maintain a consistent pH, so using these is risky.

Change Your Substrate

There are a few materials to raise the pH level, which are easy to find out and add to your aquarium. This may perform in the same way as adding tannins to lower the pH level.

The best choices would be limestone, crushed coral, petrified coral, and some other shells.

The shells and coral skeletons are known to contain a high level of calcium carbonate compounds them.

These are common in the African Cichlid tank which is known to have a higher pH than most.

Remember to test the pH regularly after you add them. Your pH level could easily go higher than you think.

If your intention is to hide the materials, you can incorporate them into your aquarium filter.

Boil Driftwood

If you own any bogwood /driftwood in your aquarium, this may release tannins and tannic acid, which causes lower pH.

The simplest method to solve this issue is to remove the driftwood from your tank. You could try boiling it if you are intended to keep it in your tank setup. Doing it regularly can kill any problematic bacteria from your tank.

Be cautious because some other materials may release tannins too, like peat moss.


Planted Tank Raise pH: A total transformation is given by adding the Macroalgae to your aquarium that you might have always wanted. Your fish tank will now have the look of a real seabed.

People might wonder why to use algae for increasing the pH instead of removing it. Can aquarium plants raise pH? These are the beneficial type of algae. This will help to raise the pH level of the water and still get rid of the other unnecessary algae found in the fish tank water.

Finally, you will always end up with a healthy and strong aquarium with the right pH just like it is supposed to be.

You will be happy to know, it is the cheapest and less tedious way of making sure that the aquarium water remains at the right pH level. Once the algae are set in the aquarium, you would not have to do anything extra.

Let it grow in a simple way to keep the pH within the desired and decent range. This type of algae is also good to act as a source of minerals and food for the marine life inside the aquariums.

Only in Shallow areas, algae can live on the seafloor.

In the end, keep an eye on the algae reproduction so that it does not become overgrown to end up spoiling the beauty it had created.


How can I raise my pH naturally?

Mixing 1 teaspoon (4 grams) of baking soda in 250 ml of water can increase its pH and make the baking soda more acidic.

How do you raise the pH in a freshwater aquarium?

According to McComb, an easy and efficient method to increase and stabilize the pH in freshwater aquariums is to alter or add the substrate and add shells. This is particularly helpful when your drinking water from the tap is dull.

Can you use baking soda to raise pH in aquarium?

You can increase the aquascape’s pH with baking soda added to it. But, prior to increasing your pH, we advise taking your fish out and placing them in an in-water quarantine tank. Once you’ve tested your water’s pH and are satisfied that it has back to its ideal levels it’s time to return your beloved pets to the main tank.

Why is my pH so low in my fish tank?

The most important factor determines the origin of the water. If the tap water you use is low in pH, and you fill up your tank, the tank’s water will also be low in pH. Tap water’s pH could change from time to time. If you notice a drop in the pH of your tank after having completed a water change take a look at the pH of your tap water, too.

How do I raise the pH in my aquarium without raising alkalinity?

The only way to boost pH without affecting alkalinity is by reducing the CO2 in the tank. You can do this with a CO2 scrubber or running an air conditioner outside. You can also install an air exchanger in order to lower the CO2 levels within your home.

How much baking soda do I add to raise pH?

The rule of general application is 1.5 pounds. of baking soda for 10,000 gallons of water. This will raise the alkalinity to about 10 ppm. If your pool’s pH is lower than 7.2 then add 3 to 4 tons of baking soda. If you’re just beginning to add chemicals to your pool, start with a small amount, such as 1/3 or 3/4 of the amount recommended.


Every fishkeeper experiences some setbacks when caring for their fish. Some people must deal with the disease and others should have to separate the aggressive tank mates.

If you happen to have any problem with the pH level, you would now feel much more better and confident about how to deal with pH. You need not panic, there are so many options available.

It is necessary that the pH should match the preferences of your fish, however, at the same time, it is also important that the pH remains stable.

If you follow one or more of the suggestions mentioned above, your tank’s pH level should be back to the previous normal position in no time.

Are you experiencing problems with your pH? Do not hesitate to ask us anything regarding this in the comments section below.


Dibyajyoti Bordoloi is the creator and author of, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.