How to Lower the PH in Your Aquarium Safe Yet Efficiently

how to lower the ph in your aquarium

Are you questioning how to lower the pH in your aquarium and trying to pick the best way to do so? Then, you should never miss our helpful suggestions below. By employing only peat moss or almond leaves, your problem will be fixed promptly.

Furthermore, you can learn to determine the right level of pH level and how to notice the symptoms of high pH in fish tank band. Curious yet? Scroll down now!

Ways To Lower The pH In Your Aquarium

#1 Changing Your Tank Filter Or Cleaning It


If the pH level in your tank rises, it might be related to the tank filter. Therefore, you might need to change the filter, which is recommended after 3 – 6 months of use, depending on how dirty it gets.

If you have not used the filter for too long, clean it by rinsing it gently with fresh water and using a sponge. Cleaning helps take off all the bacteria/dirty particles.

#2 Employing A Reverse Osmosis System


This method works better with the bigger tank (RO systems are usually quite big), and it might cost more. However, you can assure that the pH level in your tank will definitely go down and be maintained efficiently.

#3 Adjust The Aeration In Your Fish Tank


Since the CO2 levels closely affect your tank’s pH level, you can surely decrease pH in aquarium by raising the CO2 levels. Therefore, cutting down the oxygen by turning the aeration system to lower mode will help you increase the CO2 density and fix high PH in fish tank.

However, it would help if you continuously watched the oxygen level inside your aquarium, so it doesn’t drop too much and unexpectedly kill your pets.

#4 Employing The CO2 Injection Or Using CO2 Supplements

Taking the same principle as before, we will use tools and substances instead of waiting for CO2 levels to rise naturally. With both of these, you need to buy one at the store and follow the instructions to employ into your tank.

Don’t worry, the CO2 injection systems are not that expensive, you can still find some more cost-effective products in the market.

#5 Changing The Tank Water Little By Little


The most frequent reason why your fish tank’s water is the organic waste accumulated after time. Therefore, changing the tank water is a way to naturally lower pH in the fish tank.

Remember to change 20-30% of the tank water (each time) with fresh water only because it’s more handy compared to replacing the whole thing at once.

Don’t forget to clean your tank’s decoration and alter the water more often to prevent filthy waste and algae.

#6 Applying The pH-Supporting Chemicals


This might be a fast and convenient way to lower aquarium pH but it’s actually not the most recommended method. It’s because the problems will also come back quickly, and your previous issues aren’t not addressed completely.

However, there are still many useful products on the market, so you may choose a new decent one to test for the first time.

#7 Using Indian Almond/Catappa Leaves


Indian almond leaves or catappa leaves are always one of the most famous natural pH-neutralizers, so feel free to toss some into your tank and wait for the magic to happen. Yet, there are still a few things you should notice:

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  • Remember to watch the pH level status inside your tank. If there is any major fluctuation, please take the leaves out and dilute your tank water immediately.
  • To avoid organic waste, discard the almond leaves from your tank after 1-2 months. Because these leaves will only have an influence on the pH level for the first two weeks, you should consider removing them sooner.


#8 Using Driftwood


Driftwoods contain a lot of tannins (a kind of weak acid) that are assured to help you reduce aquarium pH. The first thing you should do is to boil the piece of wood before tossing it into your tank.

With this, you will eliminate the excess/unwanted bacteria/algae inside it and minimize the yellowish hue, which will be released to your tank later.

#9 Using Peat Moss


Peat moss is a must-known way to bring pH down in fish tank and here are how to use it:

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  • Find some of them at the nearby garden store or else.
  • Soak your newly-bought peat moss in water (which has the same parameter as your tank) for a while to minimize the tannins leaking into your tank afterward.
  • Put some into the tank’s filter and wait for a while.
  • Measure the pH level again to know if the pH level is lowered or not.
  • In case the pH level doesn’t drop, add more peat moss into your tank’s filter until the level meets your requirements.


Note: You can skip the soaking step if you don’t mind your tank water becoming yellowish later.

#10 Using Vinegar


Yes, change pH in fish tank with vinegar is possible, but it only works in the short term.

What to prepare

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  • A container
  • Some white vinegar
  • pH testing tool
  • Timer
  • Fresh water
  • Stirrer


Detailed steps

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  • Fill up your container with freshwater and let the whole thing wait for about 12 to 18 hours.
  • Test the pH level inside your fish tank.
  • Put in some drops of white vinegar into the freshwater container and test the pH.
  • Repeat the action until the pH level meets the target. Overall, you might need ½ teaspoon of white vinegar with every 10 gallons of freshwater.
  • Let the vinegar-mixed water wait for a few more hours before pouring it little by little into your fish tank.


What Is pH And Its Importance In Fish Tanks?

pH level (also known as the power of hydrogen) simply shows the acidity or alkalinity inside your fish tank and these chemical indexes are pretty important to fish’s lives. If you want your fish to live healthily, you should always monitor the pH or the sudden fluctuations will kill your lovely pets.

Yet, the required pH levels are distinguished between different kinds of tanks. For instance, in freshwater aquarium, the pH level must be around 6.5 to 8. Meanwhile, in saltwater aquarium, you need to maintain the pH level around 7.9 to 8.5.


How to know if the ph level is fluctuating?

There are a few tips that you can utilize in this case:

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  • Look at your fish, if it swims uncontrollably in an up and down direction continuously, the problem may be in the pH.
  • Test your tank water’s pH at least once in every 4 or 6 weeks to detect any early sign of pH dropping or rising.


How to test pH levels for fish tanks?

I recommend the pH test strip or pH test meter because these things are pretty approachable. Otherwise, you can also measure the pH with boiling water and grated red cabbage. This method might take around 30 minutes but it will work as well.

What is the ideal pH level for fish tanks?

As mentioned above, the pH level should be around 7.9 to 8.5 in a typical saltwater/marine tank and around 6.5 to 8 with a freshwater one. If there are higher or lower pH levels in fish tank than those, you should take action immediately to keep your fish healthy and happy.

Is high pH in aquariums bad for fish?

Yes, it is. It’s because pH levels affect the waste offloading process of your pet fish, which directly causes various health issues or even leads to death.

How to increase the pH levels in fish tank?

I highly suggest you try raising the pH level with baking soda. The pH level of baking soda is about 8.4, so you should be careful and follow the ratio of 1 teaspoon per gallon of water strictly.

This is also a helpful way to lower acidity in fish tank that you should never neglect. Besides, you can also use peat moss or employ the reverse osmosis (RO) system. Trust me, they can all assist you in increasing the pH levels.


No more panicking whenever the aquarium pH too high from now on as I have already provided all the possible answers to your question, “How to lower the pH in your aquarium?”.

Fret not, all of the above suggestions work and you can freely apply them to fix your tank’s issue. In case you have any other questions, feel free to leave them in the comment section and I will help you out as soon as possible.