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How to Soften Aquarium Water (5 Easy & Effective Methods)

How to Soften Aquarium Water (5 Easy & Effective Methods)

5 Effective & Easy Methods to Soften Hard Water

Well, wherever you live in this world, water hardness may not affect you as much as it can affect your aquarium.

The hardness level of the tap way can adversely affect the inhabitants present in your tank.

Therefore, you may want to know how you can soften the aquarium water. So, in this article, we are going to learn how to soften aquarium water effectively.

This guide is to highlight all the possible ways on How to Soften Aquarium Water and I’ve shared 5 methods that you can use and soften your aquarium water.

Just to remind you – water hardness is the level of natural minerals that are dissolved in the water. 

Generally, there are two categories of water hardness – one is General Hardness and another one is Carbonate Hardness. We will also learn the difference between General Hardness and Carbonate Hardness later on in this article.

Now, the major question is how can we soften the water of our Aquarium? I have shared five different types of methods that can b used to remove the water hardness and soften the aquarium water.

The Five Methods that we are going to discuss in this article ” how to soften aquarium water” today are – 

  1. Rain Water
  2. Peat
  3. Driftwood
  4. Water Softening Pillows
  5. Reverse Osmosis
How to Soften Aquarium Water (5 Easy & Effective Methods)
The Ultimate Guide To Soften Aquarium Water (5 Easy & Effective Methods)

How to soften aquarium water using this 5 method effectively

Each of them has its advantages and disadvantages, making them not suitable for all use cases.

But no worry, we will take a closer and detailed look at each of them. Without wasting time, we should learn water softening techniques.

How to Identify if Your Tank Water is Soft or Hard?

Several ways can be used to identify whether your aquarium water is hard or not. The most common and easiest method is to look for rings or scum left in the sink and bathtub or for scaling within the kettle after use.

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If you notice or feel any white deposits at the bottom, then there is a 99 percent chance that your water is hard. 

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If you want to check scientifically, then you can use a testing strip. You can easily easting purchase them from nearby stores for only a few bucks. A testing strip can give you good signs or indication on water quality, mean to say – whether your water is hard or soft. You can easily identify by matching the test strip color to a chart.

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Another alternative is to call your local water company to check your tap water quality. They can easily tell you whether your tap water is hard or soft. You can also go online and check the maps whether the water in your area is hard or soft.

What type of water is referred to as Hard water?

Water hardness is the level of natural minerals that are dissolved in the water. Generally, there are two categories of water hardness – one is General Hardness and another one is Carbonate Hardness.

General Hardness (KH)

This type of water (GH) will have both magnesium and calcium dissolved in it and the amount of general hardness depends on the number of dissolved minerals in the water. Many aquatic species struggle to thrive in hard water that has a hardness rating over a certain amount. 

Tropical fish is the best example of this as they can’t survive in this type of water for too long. Well, the certain or ideal amount of hardness varies from species to species.

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Carbonate Hardness (PH) & (KH)

This type of water differs from general hardness and has a carbonate hardness rating (KH) is measured by bicarbonate and carbonate ions present in the water. The level of carbonate also affect indirectly on the buffering capacity of water  

The amount of carbonate hardness and the Ph level fluctuation in an aquarium has a direct correlation. 

For example – The amount of KH level affects the amount PH level, the higher KH Level decreases the PH level fluctuation in an aquarium. If the water has a lower KH value, you can expect some fluctuations in your aquarium water PH level

If you face any issues with the PH level in your aquarium, then you should check the Carbonate Hardness (KH) levels in an aquarium.

I know, it is a little tricky because they are linked very closely. So, any change in the KH level will impact the PH level of water.

Fish Species that can tolerate hard water.

Several tropical fish species can easily tolerate hard water. If you don’t want to take so much hassle of softening your aquarium water, then you can keep or pet these species in your aquarium. 

Platies, Mollies, Swordtails, and Guppies are some livebearers that can tolerate and happily live in hater water. There are other species like Cichlids, Monos, Scats, Archers, and Paradis fish that can also tolerate hard water.

Now, it will make you certainly make you wonder what fish are suitable for a hard aquarium.

Before you stock an aquarium, it is very essential to provide a comfortable and happy life as possible. Being a pet owner is a responsible job, so always do your homework and research on fish petting and caring

If you avoid your responsibilities and didn’t prefer to take proper precautions, this can lead several inhabitants living in your aquarium to death very soon. No one will want to afford and end with something like this.

  • Your first goal should be to create and provide a healthy environment for your fish to live in. Commonly, tap water can be used in the aquarium as long as it is chloramine and chlorine-free. Make sure not to put your fish in hard water
  • There is one simple rule that everyone should follow while they do their research on tropical fish species – if you live in a hard water area and you want to keep fish that only lived in soft water then it is very crucial to avoid using tap water without treating it – first.
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  • There is one more thing that I would like to add – If the species that you have chosen is suitable for hard water aquarium, then it is still a must to look out for the signs of stress.

Keeping your aquarium inhabitant happy and happy will make them more energetic and will display the correct colors. If you find them active and energetic then it’s a good sign that indicates your aquarium water and their inhabitants is fine.

“Also Check”

How to Soften Aquarium Water?

It is not as hard as you think to tackle water PH & KH level hardness. You can easily treat them and soften your aquarium hard water rather than starting from scratch. 

You should often measure the hardness level using testing strips. Testing strips are very less pricey and work amazing. You can also try an electronic tester but I would recommend you avoid it unless you have extra dollars left in your garage, electronic testers are a bit costly.

The methods are easy to follow and work perfectly in softening your hard water. You should always use this method gradually if you are changing the hardness level in an active tank because sudden changes in hardness rating can drive serious problems to your inhabitants or fish-like illness or worse.

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Here are the five methods that I have shared with you that can effectively change the hardness rating of your water and make it softer.

How to soften aquarium water using rainwater?

This is the most inexpensive method to provide chemical-free water to your aquarium inhabitants.

Considering rainwater as aquarium water is the best option. You just need to store the rainwater in a container and pour it into your aquarium.

However, there are some precautions you must take before you collect rainwater.

Firstly, you should make sure that the area where you reside has decent and fresh air quality to guarantee chemical-free.

And the second one is to make sure that the storage containers or your water capturing system are cleaned and sterilized.

Note – you may need to add some aquatic salt or taper water to maintain balanced KH and GH levels to the desired level as rainwater will be very soft for some species.

Peat – ( How to soften aquarium water using peat? )

You can use peat moss to soften your aquarium water at an ideal level as it works perfectly by binding magnesium ions calcium ions. However, it will also release some tannic acid and gallic acid into your aquarium water that degrades and attack the bicarbonates present in the aquarium, resulting in the water PH and carbonate level decrease.

There are a few ways that you can use peat in water softening.

1st Way 

You can put the peat inside your aquarium filter as it will maximize the effectiveness and will ensure a constant water stream through or over the peat.

2nd Way

Take a bucket and add peat into that bucket for at least two weeks before you use it. When you feel that it is ready to use, you can simply strain the bucket water in your aquarium through a fine sieve and it’s done.

3rd Way You can submerge it directly into your aquarium by adding the peat to a pillowcase or something similar to that. Make sure to keep the oxygen levels balanced by keeping your tank fully aerated.

The only downside of using peat is it can turn the color of your aquarium to brown for a while because of the tannins it releases but it is completely harmless. Still, it will make your aquarium unattractive but no worry, it will disappear by itself after a time.

Note: It doesn’t matter what way you decide to go with as long as you sterilize the peat by boiling it for a few minutes. Plus, always purchase and go for untreated peat with no additives. 🙂

Driftwood – ( How to soften aquarium water using driftwood? )

Driftwood helps in reducing GH levels and PH levels of water and works similarly to Peat. Driftwood helps to avoid species and parasites from infesting your beautiful aquarium.
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You can purchase the driftwood online from the local fish store. Avoid low quality only because of inexpensive. avoid a nasty surprise, your bought driftwood should be boil as it will also ensure a clean start.

You will find your watercolor turned brown if you d=submerge the driftwood directly in your aquarium. Same as peat, it also releases tannins but it is completely harmless to fish but still you might want to avoid something like this from happening, 

There is one method that you can use to prevent the change in watercolor. You can soak the wood for 15 days or a couple of weeks before you use it in your tank.

As soon as you add the driftwood to your aquarium, confirm the aquarium water whether it is well aerated and moving or not.

For the first couple of weeks, I would recommend you keep an eye on the growth of slime algae or many others.

Changing your aquarium water more frequently can someway prevent this. 🙂

Water Softening Pillows – ( How to soften aquarium water using water softening pillows? )

You may question yourself, what is a water softening pillow and how to use it. No worry because we are here to help.

A water softening pillow usually uses an ionized resin that acts as a chemical filtration media.

The water softening pillows works best in reducing the magnesium and calcium level. It can effectively reduce the hardness of your aquarium water but will increase the amount of sodium level.

The water softening pillows are very effective in reducing the GH level and can be easily added to your existing aquarium water filter.

They work amazing for tanks that are smaller than 25 gallons but this doesn’t mean that it can’t be used for a larger tank.

They can also be used in a larger tank, but the only issue with the larger tank is, you have to recharge it more often

The only downside of using a water softening pillow is that they increase the sodium levels, which can affect your fish health in some circumstances. You can buy an RO unit if you can afford it and have extra space.

Reverse Osmosis – ( How to soften aquarium water using reverse osmosis method? )

Do you want to try a way that can effectively reduce your water hardness? Luckily there is one method that can effectively do this work for you. Reverse Osmosis is one of the best and efficient ways to reduce the hardness of your water.

Reverse Osmosis can remove almost 95 percent of the chemicals, minerals, and other dissolved particles from the water that results in leaving behind only pure & clean water.

Reverse Osmosis forces the hard water at very high pressure through a slightly permeable material. It only allows the clean water to pass through by leaving any contaminants behind it.

Using a Reverse Osmosis is a slow process and you may need to add tap water with the Reverse Osmosis filtered water as it is essential to find a balance of softness and hardness. You can also add aquatic salt mixtures to maintain the PH level in an aquarium.
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Note: you should record all the quantities, steps, and outcomes of the process to make it easier for you when you need to repeat the whole process again and again to ensure consistency.

Maintaining consistency is a must while doing this. So, write it all down in a notepad so that you can use the same technique for future applications.

It seems like you got an idea of how to soften aquarium water


Understanding this article doesn’t need you to have a chemistry degree. You just need to know the basics of aquarium care and maintenance which can help you to have a successful aquarium. There are a few things that we learned and its worth noting.

  • Firstly, it’s easier to stock fish species that easily tolerate hard water if you’re going for the long run, as you wouldn’t need to change the hardness of the water.
  • Secondly, It has been noticed that turning soft water to harder water is much easier than making hard water soft.
  • Third, It is very important to measure and monitor the PH levels and hardness of your aquarium to have a successful aquarium.
  • Finally, A Reverse Osmosis is the best option to go for, if you want to go with something with very few downsides

I hope you will find this article ” How to soften aquarium water?” helpful. Let me know down below if it works for you. I am 100% sure these 5 methods will work, the results can vary from method to method but they will work. What is your preferred method, that is discussed in this article – how to soften aquarium water.

If you know how to soften aquarium water effectively and easily, feel free to share!

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If you have tackled the hard water in your aquarium successfully, then we would love to hear from you about your success. Let us know down below in the comment section. ( Post title: How to soften aquarium water? )