How To Soften Aquarium Water Naturally (Reduce Water Hardness)

When it comes to aquariums and fish tanks, one of the most important parts is water hardness. But, not all fish owners understand the meaning and purpose of hardness. It may be measured in terms of degrees. There are two types of water hardness including Carbonate Hardness and General Hardness. So, how to soften aquarium water? Let’s check out this article for the answer.

Soften Aquarium Water

General Hardness (GH)

The General Hardness of the water is the result of the amount of dissolved calcium as well as magnesium in aquarium water. It can be able to effect on tropical fish. So, it’s essential to know whether the fish can thrive in the water or not before you decide to place them in that water. Certain species of tropical fish can be able to live in water with general hardness.

And, some others can be able to live in soft water. That’s why it’s important to conduct research on the type of tropical fish you plan to keep in the tank. If you ignore this step, you can take several lives of fish as well as cost your money. The majority of tropical fish are capable of living in tap water as well. However, the water doesn’t contain chloramine and chlorine.

Most importantly, you need to avoid keeping your fish in water that’s too hard or too soft. If your fish can be able to thrive in soft water only, don’t place them in tap water in any way. If you still do it, it can make your fish death. But in some cases, your fish can be able to adapt well enough, especially for the water with sufficient natural hardness.

How to Reduce Water Hardness in Aquarium?

Carbonate Hardness (KH)

The level of bicarbonate and carbonate ions you find in the aquarium water is called carbonate Hardness. It is also the buffering capability of the water. Thanks to the carbonate hardness measurement, you can know the number of times the aquarium’s pH level will fluctuate. If the KH is larger, the water’s pH value is also steadier and vice versa. The fact is that there is a direct combination between the Carbonate Hardness and pH.

5 Ways to Soften Aquarium Water?

If you want to keep hardness in check, you have to measure it regularly. So, it’s important to know how to soften aquarium water. By this way, you can keep your tropical fish safe. But, just do it gradually in order not to disrupt the lifestyle and health of your tropical fish.

Reverse Osmosis

In order to reduce water hardness in the most economical way, you need to use Reverse Osmosis (R.O.) units. They can be able to remove contaminants, metals, as well as minerals from the source of the water. Also, you can use water containers for the same purpose. Most importantly, remember to maintain consistency.

Water Softening Pillows

Another way to soften hard water is installing these units in the filter of the aquarium. This is also a great method for softening aquarium water in smaller tanks. The thing you need to do is just laying the water softening pillows in the filter. Then, let the water pass through it.

API WATER SOFTENER PILLOW Aquarium Canister Filter Filtration

Fluval Aquatic Peat Granules, Water Softener

Morton Clean and Protect II Water Softening Pellets

Rain Water

For tropical fish, it’s a great idea to use rainwater. But for that, it’s essential to make sure you use the clean water. It means that you need to make sure all the aspects of the rainwater catching system are clean as well as sterile.

Using Peat to Soften Aquarium Water

Many fish owners choose to use peat to deal with hard water by placing the peat inside the filter. This way have the purpose of letting the hard water go through the peat before they come back into your tank. In addition, you can also soak the peat in a large container for about 2 weeks. Also, remember to keep the water aerated with an airstone. However, don’t forget to boil this peat first. It’s best to buy peat without any additives.

Does Driftwood Soften Aquarium Water?

Using driftwood is also an effective way to soften hard water in your aquarium. But, you need to use clean driftwood. First, you have to boil it in order to eliminate any toxins. But, you just can apply this way to smaller pieces. And, you need to pour boiling water on top of the wood when it comes to larger ones. Then, you need to scrub it with a brush.

Although tannins can’t cause any damage to your fish, it can be able to make the water look brownish. That’s why it’s essential to soak the wood in a container before you decide to place it in the tank. You need for a few weeks for this. Last, remember to add that airstone.


All of above information promise to help you learn how to keep your fish healthy. If you don’t soften hard water, it can cause severe damage to the fish. This is considered as one of the most important responsibilities of any fish owner. So, it’s important to check the levels of General Hardness and Carbonate Hardness. Hopefully, you find our article interesting and useful.