How to Lower Gh and Kh in Aquarium

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by Jason Matthews



Have you ever looked at your aquarium’s Gh and Kh levels and wondered what you could do to lower them? Well, wonder no more! Just follow these simple steps, and you’ll be on your way to a softer, less alkaline water ecosystem in no time. 

To lower the GH and KH levels in your aquarium, you can use constant water changes or change out all of its contents for new. You could also take advantage of products that contain softening pillows with acids which will help neutralize those hard-to-remove minerals like magnesium requirement without having any adverse effects on living organisms inside your aquarium.

In this post, I’ll show you how to lower GH and KH in your aquarium using a few simple methods. So read on for tips on creating the perfect environment for your fish.

Top Ways of Lowering Gh in Your Aquarium

How to Lower Gh and Kh in Aquarium

1. Constant Water Changes

This is a quick and easy way to reduce GH levels in your aquarium. Not only will it work wonders for the water chemistry, but it also removes excess waste from the aquarium. Water changes can be done by diluting old or contaminated fluids with new ones that help keep GH low-key consistent throughout all stages of life at home aquariums.

2. Using Water Softening Pillows

Using a pillow filter is one of the most effective methods for quickly reducing tank GH levels. These small, portable resins beads contain minerals that bond with magnesium and calcium to form an easily removable layer in your water – limiting their ability to attach themselves elsewhere within your aquariums.

3. Water Softening Crystals

Water softening crystals are a cheap and simple way to make your aquarium water less hard. They work by displacing calcium and magnesium ions to reduce GH levels in your aquarium.

4. Lowering the PH Levels

When we discuss ways of lowering aquarium GH, it’s essential not just to think about the alkaline or acidic nature of your water. It may seem odd at first, but one way you can help reduce existing minerals in an environment is by buffering capacity- which means higher pH levels will allow more holding on new minerals that will make your water hard.

Related: Easy way to lower pH levels

Top Ways of Lowering Kh in Your Aquarium

1.   Using Acid Buffers

When you use an acid buffer, it is essential to go slow. The purpose of this chemical agent is typically for reducing KH levels and creating more CO2 in the aquarium water so that plants will thrive, but be careful with how much power they output as too high concentrations can cause damage or death if breathed by fish living inside your aquarium.

2.   Mixing Tap Water With Distilled Water

Using this process, you can lower your aquarium’s KH level and remove all impurities. This will leave pure water without any followers or other elements present in it.

However, you’ll need to mix it up, so the ratio between tap water versus distilled water is suitable for what works best with fish ailments or the plants in your aquarium.

3.   Create Pure Water

When you’re looking for a way to get rid of all that pesky KH in your water, two methods can be used. One uses a reverse osmosis system, and the other involves installing deionization filters- both will make water pure without any additives or residuals from minerals.

The price tag on these setups may seem hefty, but once they’re installed, it’ll pay off big time as it will save you a good amount of money.

4.   Release Tannins Using Indian Almond Leaf

When you add Indian almond leaf to your freshwater aquarium, it will start breaking down and discharging tannins (tannic acid). This is great for lowering the KH in betta fish tanks or other aquariums.

With this method, the tannins slowly consume your KH and pH levels. You must be careful not to lower it too much, though, because that would cause alkalinity recovery issues once you resume regular water changes.

5.   Release Tannins Using Peat Moss

When you add peat moss to your tank, it will help lower the pH and KH levels. This is because of its ability to release tannins essential in reducing the KH levels. All you need to do is get a mesh bag and place peat moss in them, after which you place it in the aquarium filter.

Frequently Asked Questions

How Do You Lower GH and KH in a Freshwater Tank?

Frequent water changes are the key to lowering GH and KH levels in your aquarium. Use a softening pillow on top of your filter, and add some crystals for an even better experience.  Don’t forget about removing any tap stains that may be present to ensure they don’t damage anything else.

How Do You Adjust GH and KH in an Aquarium?

To raise both the GH and KH value, add calcium carbonate. Two teaspoons per 50 liters will increase your GH and KH by about 4 dH. You can also use seashells or coral for this purpose; it’s up to you what type of filter media suits best with your needs.


Changing your aquarium’s water is a great way to lower the Gh and KH levels. It will also help keep fish healthy, which can lead to increased sales for you.

If this has been something that has been on your mind lately, try adding some new information from this post, so it becomes easier for you to get started. We hope these tips have helped answer any questions about what goes into lowering GH and KH levels in your aquarium.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

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