how to soften aquarium water safely

Having soft water in your home is beneficial in many ways. The lack of chemicals and minerals in soft water gives you clean, pure, better-tasting water, keeps your pipes and appliances running efficiently, and gives you more luxurious locks and moisturized skin. It’s easy to see why most people prefer soft water over hard water. But what about fish? 

If you have an aquarium in your home, you might have assumed that your fish also prefer soft water. Or maybe you didn’t think about it all. But fish can be finicky about water quality. If the water hardness and pH levels in an aquarium are not within the acceptable parameters for specific species, it can cause your fish stress and even death. That’s why it’s important to understand how to soften aquarium water safely.


Hard Water vs. Soft Water

The hardness of water is defined by its levels of minerals like calcium and magnesium. The higher the amount of the minerals, the harder the water. You can determine the type of water in your aquarium by checking for the formation of limescale and patchy deposits on the glass.

Many fish can only thrive in certain ranges of water hardness and pH. Usually, having hard water means your water has a high mineral content and a high pH. In contrast, soft water typically has a low pH. To prepare your water and create a fish-friendly environment, it’s best to determine which fish species you want in your aquarium ahead of time. Then, you can tailor your water to the proper pH levels to ensure their happiness and wellbeing. 


Risks of Softening Aquarium Water

Depending on the species of fish you bring into your home aquarium, soft water conditions are generally preferable. But if your water is too soft, it can create a whole different set of challenges for your fish and aquarium.

Reduces the Efficiency of Bacteria

Bacteria and filters are essential to the life of fish and aquariums. Filters trap bodily waste and oxygenate water by agitating it. The bacteria keep the fish alive by breaking down fish waste into ammonia to keep nitrate levels from rising. But if the water is too soft, filter bacteria may not work as well.

pH Instability

Naturally, all aquariums become more acidic over time. But when using soft water, these changes in pH can happen quite rapidly. Fish do not tolerate these changes well, so be sure to perform frequent pH tests and use chemical buffers in soft water.


Benefits of Softening Aquarium Water

Overall, as long as you have fish species that prefer soft water, soft water promises more benefits than risks.

  • Soft water keeps limescale and mineral buildup from forming on your tank, which makes cleaning your aquarium much easier.
  • Aquarium appliances like filters and lights last longer in soft water.
  • There are many more species of fish that prefer soft water, widening your selection of options. 
  • Soft water is cost-effective in the long run. If you install a whole house water filtration system or water softener, you will save even more money on bottled water, appliances, plumbing, and bills.

Just make sure your aquarium water isn’t too soft. Fish still need certain minerals to thrive and live a happy, stress-free life.


Ways to Soften Hard Water

Reducing hard water in your aquarium for specific fish species may feel like a tedious and daunting task, but there are many ways of accomplishing this goal.

Water Softening Pillows

These pillows are the preferred method for smaller tanks. They contain ion exchange resins to remove calcium, magnesium, and soluble heavy metal ions to help stabilize the pH while eliminating the mineral deposits from your tank. Place these pillows in the filter of your aquarium for quicker results.

Many of these water softening pillows can be recharged and reused multiple times. Do this by dissolving three tablespoons of aquarium salt in seven ounces of tap water. Rinse the used pouch in tap water and then soak it in the salt solution for two hours before placing back in the filter.

DIY Peat Moss Filter

Peat moss affects the chemistry of your aquarium water by filtering out minerals, releasing tannins, softening the water, and lowering the pH.

The best kind of moss is cheap and untreated. Check to make sure it has never been treated with fungicides and does not contain any additives. If the moss is expensive, it’s the wrong type. 

To use the moss:

  1. Put it into the foot of a new pair of clean nylon stockings.
  2. Tie off the stocking and cut off extra material. Boil the pouch of moss in hot water until the water turns black.
  3. Remove the still-tied stocking, squeeze out the excess water, and rinse it before adding it to an aquarium sump, hang-on filter, or an empty compartment in a canister filter. Here, it will leach away tannins and absorb various minerals.


You can buy driftwood online or naturally source your own. The best time to look for driftwood is immediately after a storm near oceans, lakes, rivers, and creeks that have surrounding vegetation. After choosing your driftwood, boil it to get rid of toxins. You also might want to scrub it with a brush for extra assurance. 

Driftwood has the potential to lower the pH level and soften the water in your aquarium. This is due to the tannin acids that leak from the driftwood into the water. These acids have naturally antibacterial properties that benefit the immune system of your fish.

Reverse Osmosis Filtration System

Reverse osmosis is a process of ionizing water and pushing it through a semi-permeable membrane to filter it down, reducing contaminants and minerals. By default, this also softens the water. This clean, purified water is great for drinking, cooking, cleaning, and filling your aquarium. The Science of Water offers whole house reverse osmosis water filtration systems from Puronics that can benefit your home in many ways.


The Science of Water

At The Science of Water, we offer multiple whole home water filtration systems, and we are positive there is at least one option to perfectly suit your needs. Visit our website to request your free water test, and we’ll help accurately determine which of these systems are best for you, your family, and your fish.

We are proud retailers of Puronics water filtration systems and water softeners. Puronics uses SilverShield® Protection NASA Technology, and selected products have even been tested and certified by the Environmental Protection Agency (EPA). 

Contact The Science of Water today and let’s get started ensuring you have clean, pure water available at the touch of a faucet. Your family and your fish will thank you.



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