How to lower pH in Fish Tank – safely and beginner friendly

It is a worthwhile experience to have an aquarium in your house. If you’re an aquarist, you should know that the aquarium’s ecosystem must be adequately maintained to keep your fish alive and healthy. Besides, maintenance helps you to prevent some issues along the way.

One of the factors to consider when taking care of your fish is to know the water’s ideal pH. If you have been struggling with lowering your pH for a while, this guide will help you. You need to maintain a specific pH and know how to measure it to keep your fish happy.

Thus, we will guide you on how to lower your aquarium’s pH quickly to avoid an early death from your fish.

Short Answer

When your water’s pH in an alkaline range or above 7, you notice your fish weakens over time. Hence, lower the pH level until it reaches the ideal range. Fortunately, there are techniques you can reduce the pH of your water. In this way, the fish will be able to survive.

These methods include changing the water frequently, adding a new filter and reverse osmosis, decreasing oxygen levels, and adding ornaments such as peat moss, driftwood, and almond leaves.

Long & detailed Answer

What is pH in an Aquarium?

We have certainly heard of the word pH. However, most of us do not know the importance of maintaining certain pH levels in our aquarium.

The pH measures the acid and alkaline levels in the water. It ranges between 0 and 14. A pH level of 7 indicates it is neutral, while below it is acidic and above is alkaline.

When an acidic or basic substance enters the aquarium water, the pH of the water changes.

These substances that affect the pH level include trace minerals, chemical concentration, and type of substrate.

Different fish species react to varying pH levels. A certain pH level might not work for one fish but works for another type of species.

This is why it’s essential to research fish before buying and adding it into your tank. You need to ensure that the pH level of water and the needs of the fish are compatible. In this way, you can ensure your fish will live longer.

What happens in the Aquarium if the pH is too high?

If the water in your aquarium is too high or alkaline, the water gets cloudy or colored from the leftover food or fish waste. Once this happens, the water will burn the fish’s scales.

Another way to identify a high pH level is when you notice your fish darts back and forth repeatedly. By then, you need to lower the pH of your water tank. If you leave the water’s pH as it is, it will cause death to your fish.

How can I test the Water pH?

Test the water pH by using a pH test kit. If you notice the water pH level is too low, let’s say for at least 5, it becomes acidic.

With this, add crushed limestone to increase it until the pH level becomes 7. You can also eliminate the carbon dioxide present in your water by aerating the water with an air pump.

If you live in an area or city with hard water of high pH, add an acid buffer to lower it. Frequently check the water by using the test kit to make sure the pH reaches 7.

Our recommendation for a test kit: Tetra EasyStrips 6-in-1 Aquarium Test Strips

Read more about it here: Best Aquarium Test Kits.

How can I safely lower my Aquarium’s pH Level?

The pH levels in the water tank change depending on the substances you place inside. However, high pH levels are the most common issue. If you find the pH too high, you can follow these methods to achieve your aquarium’s optimal level.


Change Water Regularly

One reason the water has too much high pH is because of the presence of ammonia. This ammonia results from fish waste and leftover food from the tank. This is why you should change the water regularly.

By changing the water regularly, you can stabilize its pH level. Also, keep in mind to clean the decorations to remove debris and algae before loading the new water.


Buy a New Filter

If your current filter cannot efficiently clean the waste from your water, you need to get a new one. However, there are times that cleaning will suffice.

Remove the sludge when cleaning the filter to eliminate the debris and bacteria lingering for a while. Clean the filter with water instead of using chemicals.

Our recommendation for a filter: AquaClear Power Filter


Add Peat Moss

Another way to lower the pH of your water is to add peat moss. Besides, adding peat moss will certainly do marvels for your fish.

However, it can stain your water into a yellow tinge. For this reason, place the peat moss into a container for a few days before you transfer it to your aquarium. Also, add the right amount, as too much of it can harm your fish.


Add Driftwood

Adding driftwood to your aquarium will create a better environment for your fish, making it more similar to its natural habitat.

Before adding driftwood to the water tank, make sure to get rid of any contaminants that might be infesting by boiling it into hot water. In this way, you’ll prevent polluting the water.


Add Catappa or Almond Leaves

One creative way to reduce your water tank’s high pH level is to add Catappa or almond leaves.

Before adding it into the aquarium, make sure to soak it into the water to prevent it from adding color to the water.

Furthermore, by adding almond leaves, you’ll create a refreshing look to your aquarium. You’ll also create a better environment for your fish.


Buy a Reverse Osmosis Filter

Using a Reverse Osmosis (RO) filter removes the ions and molecules in the water to ensure it is clean. Hence, all contaminants are removed with an RO.

The RO filter works this way: It allows small ions to pass through into the water while preventing the heavier ones that could damage the fishes.

While installing a RO filter sounds expensive, it is the most effective method to lower your aquarium’s pH. It will also ensure that the water in your tank is at optimal pH levels, especially if you’re using hard water.

Moreover, keep in mind that this kind of filter is big and only suitable for huge water tanks.

Our recommendation for a Reverse Osmosis filter: AQUATICLIFE Four Stage Reverse Osmosis Deionization Unit 50 GPD


Decrease Oxygen Levels

Decreasing aeration or oxygen levels will undoubtedly lower the pH of your alkaline water. Therefore, it increases the water’s carbon dioxide levels, which reduces the pH.

You need to be cautious about increasing the level of carbon dioxide in the water. Too much carbon dioxide will eventually lead to the death of the fish.

Make sure to take the precautionary steps when lowering the oxygen levels in your water tank. Adjust the aeration only until the pH reaches around 7.

What influences the pH Level in my Fish Tank?

Many factors can affect the pH level in your fish tank. Besides, we need to maintain it at an optimal level to ensure our fish is alive and healthy.

Aside from the factors above that can lower the water’s pH, the following are the things to consider that can lead to a higher or extremely low pH of your water.

  • High nitrates can drop the pH of the water waste and other pollutants.
  • Crushed coral, substrate, or ornaments can increase the pH levels (which is recommended to add if the water is too acidic)
  • Hard water
  • Use a water purifier to decrease the pH levels of hard water
  • Overstocked aquariums

Stabilizing the water tank’s pH is crucial for the fish to better adapt to its environment. Even a minor change in the water’s pH level can cause distress to the fish. With this in mind, test the water daily as the pH changes throughout the day. Ensure to use a pH test kit that is not expired.

How can I acclimate a new Fish to the pH in the Aquarium?

You should quarantine your newly bought fish for two weeks by placing it into a community tank before adding it to your aquarium. However, if you don’t have a community tank, you can follow these steps to acclimate your fish to your aquarium.

  1. Open the Plastic Bag.
    Newly bought fish is placed in a plastic bag. Once you get home, put the bag in the tank. But before you do it, roll the top of it to allow it to float into the tank.
  1. Get Water from the Tank and Add it to the New Fish’s Plastic Bag.
    Adjustment is a slow and steady process. To start, add a ½ cup of tank water into the plastic bag. Do it again after 15 minutes.
    This process will help your fish adjust to the pH changes and other factors such as oxygen content, nutrient levels, and salinity.
  1. Test the Water from Your Tank.
    Now check the quality of the water if it is an ideal environment for your new fish. Make sure the water is clean from debris, waste, and molds.
    You should also test the pH and temperature regularly. Add the fish into the water only after doing the parameters to ensure the tank is possible for fish occupancy.
  1. Add the Fish into the Tank.
    It’s time to add your fish to the tank. Make sure to test the pH of your water daily. Also, check the filter, color of the water, and the cleanliness to prevent the pH from shooting up.

Conclusion – How to lower pH in Fish Tank

Maintaining the pH level of your water is crucial to keep your fish alive and healthy. Even a small difference in pH may cause shock to the fish, leading to its death. The more significant the difference in pH, the more chances your fish will die.

When you notice your water gets dirty, clouded with ammonia and color, the pH is likely increased. Hence, follow the methods above to lower the pH. Then, test the pH regularly to ensure the life of the fish.

Also, when buying a new fish, acclimate it by adding water slowly into the plastic bag. Once it has been adjusted, you can add it to your fish tank. In this way, the fish won’t get shocked by the sudden changes in the environment.

Remember, you are trying your best to increase the survival of your fish. One way to do it is to lower your fish tank’s pH until it reaches the optimal level.


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