5 Killer Ways to Soften Aquarium Water

This entry is part 7 of 7 in the series Water parameters
Rosy Fin Tetra” by Moto “Club4AG” Miwa

Softening your aquarium water requires you to remove some dissolved minerals  that hardens your water. 

How do you soften your aquarium water?

What are the most effective methods  for softening your aquarium water?

I know you are probably eager to see how you can soften your aquarium water right now but most times,  the softness of aquarium water does not come first.

When you keep water hardness in consistent check, it may also follow that you are also trying to determine whether the softness of your water is still intact.

What am I talking about? I will dive in water hardness first, then you can figure out how you can soften your aquarium water in the subsequent heading.

See also:

Basic Killer Tips on Aquarium Water General Hardness

1. How do you determine whether your water is hard or soft?

There are many ways you can simply determine whether your water is hard or soft. 

So, if you are unsure as to how to figure it all out. I will show you how.

Local water company

Of course, this method may look like more of a Plan B than the real thing but honestly, it is effective.

You can simply figure out your water hardness or softness by asking any local water company around you.

Certainly, they should be able to find out whether your water supply is hard or soft.

Soapsuds test

If you are a Do-it-yourself kind of person, you can simply figure out the hardness or softness of your aquarium water by using the Do-it-yourself method.

Out of other methods, it is the simplest and easiest.

This is because you are doing it yourself. You aren’t leaving your comfort zone. You aren’t using any testing instrument nor asking anyone about the state of your water.

So, how does it works?

  • Get an empty and transparent bottle.
  • Fill one-third of it with water from your aquarium.
  • Add a few amounts of liquid soap and shake intensely for a few minutes.
  • Your water is hard when there aren’t any bubbles and the water looks milky. This is not the case for soft water. Your water is soft when there are a lot of bubbles and the water is clean from the bottom of the bottle.

Test kits

Well, the soapsuds test may be effective but it is not always as accurate as you think.

During those inaccurate moments, you just need to embrace some advanced test methods.

Test kits would perform the kind of magic you desire for your aquarium water.

Below is my favorite water hardness test kit on Amazon. It’s affordable and easy to use.

What’s more? If you are still unsure as to what testing  kits really are. I will show you:

Test kits are available in liquid form, powder and strips. 

Still wondering about how you can use them?

  • After filling a transparent container with water from your aquarium, insert the test strip for a few minutes and then remove it.
  • Observe the color change in the water.Test strips always come with some color charts.
  • If the color  change in the water corresponds with the colors in the color chart , chances are that your aquarium water is hard.

You can also  follow the same procedure for the liquid and powder form. So, there you go with your testing kit journey.

See also:

Top Rated Aquarium Test Kits For Freshwater And Saltwater Tanks (Review And Guide)

2. Hard water species?

Unless you are just the persistent one who only roots for soft water species, there are some species of fish that can actually thrive in hard water.

What am I talking about?

Actually, you may not have to soften your aquarium water in some circumstances.

This is because chances are that your fish may be the kind that can thrive perfectly in hard water.

Why? They may be the kinds that grew in hard alkalinity environment.

Sounds good? 

So, you may have to ignore the soft water thing by simply choosing the hard water fishes. They are:

  • Paradise fish
  • Swordtails
  • Archers
  • Monos
  • Mollies
  • Platies and the likes

3. How do you soften your aquarium water?

If you still think that soft water is the real thing for your fishes, then you can simply go for it.

Maybe soft water is just what your species of fish really need, there are varieties of ways you can soften your water.

Do not be surprised. Softening your aquarium water with these various methods may mean changing your water sources to an expensive source. 

Peat Moss

Peat Moss is a common aquarium water softener for fish owners. But well, there is a number of ways you can employ to apply it. I will show you how.

Aquarium filter method

This method is quite simple. You can simply add the peat in your aquarium filter so that it can flow freely in the tank.

Container method

This is simple but gradual. Figure out a clean but large container and soak the peat in it for two weeks.

Purchase only non – additive peat. Also, the peat is prone to contaminants.

Simply boil the peat to ward off contaminants. Add an air stone to keep the water flowing.

Water softening pillows

Option 1:

API water softener pillow

Option 2:

Aquarium Supplies Water Softener Pillow ION Exchange

Like every other means of softening aquarium water, water softening pillows is quite simple too.

It is considered the best method for softening aquarium water in smaller tanks. 

You know what is great about this tool? You can always recharge and use it for as much time as you can.

What’s more?

All you need to do is to install a water softening pillow in your aquarium filter, let the water flow through it and you are good to go. It is that simple.


Sure enough, softening aquarium water may be a bit expensive.

If you want to escape this expensive scene, you can just go for rainwater to soften your aquarium water. It doesn’t cost you anything. It is the gift of nature.

All you need to do is to make sure all your rain catching system are very clean.

If you are going to employ large containers, ensure that there aren’t nearby chemicals and dirt that is hazardous to the health of your fishes.

Reverse osmosis

Aside from rainwater, reverse osmosis is another way of escaping the expensive scene. This method will soften your aquarium water.

It is not only economical. It is endowed with varieties of benefits which are by far more than the ones you would get from rainwater.

Want to figure out those benefits? Keep reading.

  • Reverse osmosis will ward off minerals from the water
  • It will remove contaminants
  • It will remove metals too


Maybe or maybe not, driftwood may not be as effective as other ways of softening aquarium water but notwithstanding it is still a fine alternative.

Driftwood will produce tannins in your aquarium water and most likely, your water will change into brown color. It wouldn’t harm your fishes any way.


Now you have figured out how to soften your aquarium water.

Of course, you don’t have to be an aquarium expert for you to digest the tips above.

Being able to scan through these tips is more than enough and it is going to play a huge role in ensuring a hassle-free journey for your fishes.

Let me say this straight, it is not only humans that deserve a healthy life. While you deserve a better healthy lifestyle as a human, your fishes deserve more.

So whichever way you are going to tend your fishes, ensure you pay close attention to the hardness of your aquarium water.

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