How to raise pH in Aquarium Water?

How to raise pH in Aquarium Water? All you need to know.

Learning how to raise pH in aquarium water is crucial for amateur fishkeepers as the pH level in an aquarium keeps your fish happy. If you are new to fish keeping and don’t know how to increase pH in aquarium water or to set up an aquarium to start with, then you’ve come to the right place. Here we’ll let you know what pH is and why it is so vital for your fish, and well most importantly, how you can easily raise pH level in an aquarium naturally.

Not knowing about the pH level of your aquarium is one of the common dilemmas of people wanting to keep a fish that may end in unwanted situations. 

What is pH? 

In simple terms, pH is just a measure to know the acidity and alkaline level of your aquarium water. Measured on a scale of 0-14, a pH test can help you determine whether you need to lower or raise the pH level to keep your fish healthy. All levels below 7.0  are acidic, and all levels above it are alkaline; however, you cannot determine one pH level for your fish tank as every fish has its own needs regarding the pH level in the aquarium. Therefore, it is important to search about the inhabitant’s needs before proceeding with pH level changes. The pH level for a saltwater fish tank can be around 7.6 to 8.4; however, it mostly depends on the inhabitants, including fish, corals, and invertebrates in the fish tank. 

How to Raise pH in Aquarium?

Raising pH levels can be a very efficient way to manage a healthy aquarium life, as even a slight drop in pH level can endanger the inhabitants. At About Fish Tank, with our in-house specialists, we have curated a comprehensive list of methods to raise the pH level in the aquarium. Let us know which one worked for you in the comment section below. 


The most effective and easy way you can get to raise the pH level would be to increase the oxygen concentration in the water. Another way to put it would be to lower the carbon dioxide concentration that is one reason for the low pH level when dissolved in the water resulting in the production of carbonic acid.
The easiest way to aeration of water would be to move the aquarium filter on the surface to disturb it, eventually leading to a movement of oxygen. Alternatively, if the filter is not making much difference in the aeration, you may also want to use a strong pump or powerhead. However, it is important to choose a powerhead with an adjustable flow to control the water currents according to the type of inhabitants. 

Why pH is important in fishkeeping

Baking Soda: 

Another cost-effective way to raise the pH level would be to use the easily found baking soda. Adding only in tiny amounts can give you quick results; however, it is important to add this in little amounts as adding too much or in one go can raise the pH too quickly to cause a major spike that can kill your fish. Another thing to remember is that the pH of baking soda is 8.4, so you will not be able to raise pH beyond this and will also have to constantly add this to maintain the pH level in aquarium. It is advisable to gradually add 1 tsp per 5 gallons or less, depending on the type of fish you have. Dissolving baking soda in some water before mixing it in the aquarium also makes it less shocking for the inhabitants. 

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water changes: 

The simplest method to maintain the pH of aquarium water would be to change the water on a regular basis. However, as mentioned above, sudden pH level changes and fluctuations can shock fish and endanger their lives; therefore, avoid changing the water in one large shift. Small intervals of 24 hours between water changes with regular vacuuming and cleaning process for wastage in the water will do the job. It is advisable to replace 20% of the fish tank water every 2 to 3 weeks to remove readily infected aquarium water, making it easier for the water filter to purge.   


Most fish keepers recommend adding seashells for the pH rise in the fish tank as shells are a natural instrument to raise the pH because of their high carbonate content. You can easily buy shells from a pet store or collect them from the beach; however, make sure to wash the shells thoroughly before adding them. Two seashells per gallon will help in minor pH adjustments. Don’t rush in adding more as seashells take at least a few days to dissolve hence a gradual and slow rise in pH level. One thing to remember is not to use painted seashells as they can endanger the health of inhabitants. 

Rocks or substrate: 

Adding rocks and substrate in the fish tank is also an extensive way to raise the pH level. Few commonly used rocks and substrates are 

  1. Limestone and dolomite chippings
  2. Crushed Coral

Limestone and Dolomite Chippings:

Limestone is high in calcium carbonate content and works wonders when it comes to increasing the pH level. You can add a limestone bag instead of a coral bag in the filter as both complement each other and balance the insufficiencies of each other.

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Another natural way to increase the pH would be dolomite chippings, enriched in calcium and magnesium and can easily be found. Dolomite chippings are tiny beads with a powder coating and can easily transform into aquarium gravel and stone. 

Aragonite Substrates: 

Another natural way to increase the fish tank pH level would be to use the aragonite substrates. Initiated from oceans, aragonite substrates naturally help in pH level rise to a certain level.

Crushed corals: 

Adding small bags of crushed corals in the filter can be used to increase the pH level. It is important to add the crushed coral depending on the aquarium size as it spikes the pH level beyond intended. Therefore, monitor the pH level regularly after adding the crushed coral to avoid any accidents. For a small-sized aquarium, one small bag made of mesh or non-dyed stockings would be enough; for bigger ones, use three or more. 

Growing macroalgae:

When it comes to natural ways to increase the pH level in a fish tank, most suggest growing macroalgae inside it. It helps in maintaining the pH levels but also creates a healthy aquarium environment for inhabitants. This method is the least problematic as macroalgae naturally add essential minerals in water to keep the ideal pH level while being a food source. 


You can easily get your hands on chemicals used to adjust pH levels intended to work in a similar manner as baking soda. However, these chemicals are not usually recommended because of the risks involved in the usage in terms of major and sudden spikes and inconsistency. Chemicals are just a temporary fix and will not be helpful if you want to maintain the pH of water for a more extended period. You can turn to chemicals as your last resort if everything else seems to fail. 

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Frequently Asked Questions

What causes a lower pH level in aquarium?

There can be various reasons that your aquarium has a low pH level or had a recent drop. Decreased aeration, driftwood, soft water, the addition of Carbon Dioxide, high nitrates, pollutants, and food waste, overstocked fish tanks are few common causes that can lower the pH level in your aquarium. 

How to raise pH in saltwater aquarium?

Adding baking soda, maintaining alkaline levels with sodium bicarbonate, water aeration, and natural decors can help raise the pH in the saltwater aquarium. Read the above methods for more information and to learn how to raise pH in saltwater aquarium with baking soda in an appropriate manner. 

How to raise pH in freshwater aquarium?

Aeration, rocks and substrate, regular water changes, and removing anything that is lowering the pH levels are quick, easy ways to increase pH in a freshwater aquarium. However, each method has its own set guidelines so make sure to read the full article before applying any.


To conclude, a low pH level is very much a possible challenge that you may face while keeping a healthy aquarium life. However, it’s not a situation to panic but to strategies about how you can start working on raising the pH levels without hurting the inhabitants. Which methods worked for you best, share your story with us and many others in the comment section below.

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