How to Raise pH in an Aquarium

by Aquarium Scoop | Last Updated: October 26, 2022

One of the most common questions we get from aquarium owners is, “how do I raise the pH in my aquarium?” If you own a fish tank, it’s essential to keep a close eye on the pH levels in the water. Fish are susceptible to changes in pH; even small fluctuations can cause them stress. A sudden drop in pH can even kill your fish!

In this guide you’ll learn:

  • How to raise pH in your tank
  • Tips for testing pH
  • What causes pH levels to drop?

There are a few ways to raise pH in aquariums. You can use a commercial product, add limestone or dolomite to the water, or let the water sit for a while to allow the natural carbonates to raise the pH.

If your fish are showing signs of stress or you’ve noticed that your plants are starting to die off, your aquarium likely has a low pH level.

How To Safely Raise pH In Your Aquarium

If you’re having trouble with the pH in your aquarium, don’t worry, you’re not alone. Many aquarium owners struggle with keeping the pH at a stable level. The good news is that there are some things you can do to raise the pH in your aquarium slowly and safely. 

Add limestone

Limestone is a natural source of calcium carbonate, which can raise the pH of your aquarium. However, limestone will not raise pH quickly or substantially because it is poorly soluble in pH-neutral water. Still, it can be used as a tank decoration to help maintain proper pH levels.

Add crushed coral

Finally, you can also try adding some crushed coral to your aquarium.

Crushed coral is made up of calcium carbonate which helps to raise the pH in your aquarium. Remember, it’s important to raise the pH in your aquarium slowly and safely. If you add too much at once, it can cause problems for your fish.

Add baking soda

Baking soda is another natural source of calcium carbonate and can be used to raise the pH of your aquarium. This is a fast and inexpensive way to raise tank pH levels.

Using a pH-neutralizing filter

These filters are designed to remove acids from the water and can help raise the pH of your aquarium.

Changing the water

If your tap water is acidic, you can try adding distilled or reverse osmosis water to raise the pH of your aquarium.

Use a pH adjuster

One of the best ways to raise the pH in your aquarium is to use a product called pH UP. This product is designed to make your water more alkaline and safely increase the pH in your aquarium. You can find pH Up at most pet stores or online. Start out using a few drops and then test the pH levels. Don’t go overboard.

Add live plants

Another way to raise the pH in your aquarium is to add some live plants. Live plants help to naturally raise the pH in your aquarium. This is because they produce oxygen which helps to neutralize the acids in your water.   

Adjusting to your aquarium’s pH can be tricky, so it’s important to consult a professional if you need help with how to proceed.

Expert Tip 🧠

Acidic water, decaying organic matter, and fish waste can all contribute to low pH levels in an aquarium. To raise the pH, consider adding limestone, baking soda, or using a pH-neutralizing filter.

Test Your Aquarium’s pH Levels Regularly

If you have an aquarium, it’s important to test the pH levels regularly and take steps to raise the pH if it’s too low. Aquarium fish thrive in slightly alkaline water, with a pH between 7.0 and 8.0.

If the pH falls below 7.0, it can cause stress and illness in fish. You can do a few things to raise the pH in your aquarium.

First, you can add a product like Seachem Neutral Regulator to the water. This will slowly raise the pH over time.

You can also use a product like Seachem Alkaline Buffer, which will raise the pH instantly but need to be replenished more often. If you have live plants in your aquarium, they can also help to raise the pH. Certain types of plants, like Java ferns and hornworts, release chemicals that raise the pH. 

Finally, you can use a piece of driftwood in your aquarium. Driftwood releases tannins into the water, which raises the pH. Whichever method you choose, regularly testing pH levels will ensure your tank is healthy and your fish are happy.

Expert Tip 🧠

To raise the pH in an aquarium, use a product like Seachem Neutral Regulator, Alkaline Buffer, or live plants.

Understand What Causes Low pH in an Aquarium

PH is a measure of how acidic or basic water is. The ideal pH for an aquarium is between 6.5 and 7.5. 

Low pH can be caused by many factors:

When organic matter decomposes, it releases acids into the water. This can lower the pH of your aquarium over time.

Fish waste is also high in acids and can contribute to low pH levels.

If your tap water is acidic, it can also lower the pH of your aquarium.

Some types of bacteria can release acids into the water, lowering the pH. If you suspect your aquarium has a low pH, it’s crucial to test the water and make adjustments as needed.


Is Low Ph Bad for Fish?

Yes, low pH levels can be harmful to fish. Fish are less able to tolerate low pH levels because it can cause stress and affect their ability to breathe. In extreme cases, low pH levels can even be lethal to fish.