How Do You Keep Discus Water Quality Perfect?

The perfect water conditions for discus are warm, acidic, and soft water. The perfect pH of the water is between 6.0 to 7.0. The perfect temperature is between 82°F and 86°F (although, the temperature for Heckel Discus is 90°F). The perfect hardness is between 1° dKH and 4° dKH.

Discus are generally very sensitive to changes in water temperature and quality, ammonia, and nitrite, and so, it is important to provide the necessary conditions to keep them alive, and these include setting up their aquarium with the most efficient and reliable equipment available.

Discus tends to best in warm, soft, acidic water. The pH balance of the water should sit between 6.0 to 7.0  The degree of hardness should be between 1° and 4° dKH while its temperature should be kept between 82° F and 86°F. If you have wild Heckel discus, then you may consider 90° as the optimum temperature.

Table of Contents

Practical Tips and Tricks For A Better Discus Water Quality

Below is another water requirement a Discus Farmer should bear in mind as well:

  • You should always use an Aqueon Aquarium Heater to maintain proper water temperature.
  • Discus requires clean and fresh water quality with weekly changes of 10 to 25% using a siphon vacuum gravel cleaner or Aqueon Aquarium water changer.
  • When purchasing a discus, it is important to always ask about the water chemistry in which they were raised. While the captive-bred discus may be kept in dechlorinated tap water, deionized water, or reverse osmosis water,  that is supplemented with Aqueon water always remains the best solution.
  • Lastly, do not forget to treat tap water with an Aqueon water conditioner before refilling your Aquarium.

How Often Do You Change Water For Discus?

Discus aquariums require a frequent change of at least once every week to maintain perfect water conditions and as such, Discus water requires frequent change of water of at least once a week. Some farmers prefer to change 20 to 25% of their aquarium water two to three times a week.

A clean water environment is key to nurturing a healthy Discus habitat. Farmers who wish to rear these very beautiful, sensitive creatures must be willing to put in the work to see them thrive in their best conditions.

Note: A clean tank with frequent water changes will go a long way in maintaining a healthy lifestyle for your Discus.

There has been this wrong perspective about Discus water that it needs to be changed constantly. That’s not entirely true because very successful discus breeders tend to disagree with that. While it is good for your discus water to remain clean, it is necessary that you change your discus water at least once a week.

Note: Failure to do water changes could pose a health risk to these creatures due to the very sensitive nature of their environment.

There isn’t any strict, laid down rule pertaining to changing discus water: while some breeders may change their discus’ water 100% just once a week, others could change 50% of discus’ water twice a week, some breeders go also decide to change 25% of their discus water three times a week. My advice to you is just make sure you do change it at least once a week.

Remember that the more you change discus water, the more you tend to flush out harmful substances that could be inside the water. however, the new water should contain the same exact water quality and gradients in order to maintain the beneficial bacteria in the tank.

Discus, just like every other animal out there, tends to accustom themselves to you as their owner, so it’s important you have and maintain a steady pattern that you follow to change their water. The advantage of this is that your discus will already be looking forward to you changing their water and they’ll be prepared for it beforehand.

Healthy discus environments tipsLearn more on
How to keep healthy Discus

How Do You Soften Discus Water?

Minerals are responsible for hard water. To soften Discus water, you have to remove the mineral with a natural water softener e.g Sera Super Peat. Another way to soften Discus water is by Reverse Osmosis. This process takes out minerals such as nitrates, phosphates, and chlorine to provide perfect water for Discus health.

Note: The best solution to soften discus water naturally is to use the reverse osmosis process.

This is the best way to produce soft water from hard water. If the resources available to you are hard water, you could make do with what you have if you have the knowledge of how to reduce water hardness in an aquarium. You can simply connect a reverse osmosis unit to the source producing the hard water such as a tap, and this will strip the water of its nitrates, phosphates, and chlorine to produce very pure base water that is suitable for use for freshwater or saltwater aquariums.

The reverse osmosis method will provide you with soft water, but sometimes, your soft water might need fixing; the best way to fix soft water in an aquarium is to add a buffer because reverse osmosis could bring the pH and gH of the water to a dangerously low level. In this case, a buffer would be needed to prevent the pH and gH from crashing.

How To Increase Water Hardness In Aquarium

The most effective ways to increase the hardness of the water in your aquarium is by using tap water, crushed coal, Aragonite, water remineralizer, or Limestone. you can also dissolve 1 teaspoon of baking soda for every 5 gallons of aquarium water.

The hardness of water is caused by dissolved minerals in it, these minerals include Calcium Carbonate, nitrates, phosphates, and the likes. The addition of these substances in controlled quantities will result in the hardness of the water.

Note: Bear in mind that these compounds should be added in the prescribed amount, so you could go to the aquarium store to make your findings of the best concentration of these substances to add to harden aquarium water.

Related Questions

Do Discus Like Moving Water?

Discus does not like fast-moving water because their natural habitat is slow-moving water, it’s best to use canister filters and never under-gravel filters because canister filters create several media to enhance and maintain the water quality.

Discus belongs to the species of fish that come from slow-moving waters; thus, they won’t thrive very well in fast-moving waters.

Water flow is good, but this wouldn’t be your preferred Discus water choice. They could deal with it though, but you can tell from their reaction that they don’t really like it. So, you could stick warm, still water, or you can turn down the flow on filters or get a spray bar to remedy the situation.

What Temperature Is Best For Discus Fish?

The best temperature for discus fish is between 82°F and 86°F (28°C to 31°C). Although a species such as Heckle Discus prefers a temperature of around 90°F. You can maintain the temperature of your Discus water with an aqueon aquarium heater.

Can You Keep Discus In Tap Water?

Yes, Discus like the Stendker Discus can be kept in tap water. They were raised in German tap water. If your tap water is soft, then there is no need to get a reverse osmosis unit, otherwise, it’s safer to get an HMA to help filter off any unnecessary toxins that might threaten discus.

Do Discus Really Need Daily Water Changes?

No, Discus does not need daily water change. Water may not necessarily be changed daily, but it is important that the water is always clean and must be changed at least once a week.


Expert breeders of the discus fish have proven the best solution on how to soften aquarium water naturally is the reverse osmosis method, amongst other methods.

As a discus breeder, or potentially one, it is important to do as much research as you can containing these animals, as these shy creatures are very sensitive to changes around them. This article should serve as a guide if you need a few questions to be answered on your journey along the way.


This is me Firas Sameer, the founder of, I am an aquarist guy with a passion and love for Discus fishes, I am learning every day with my hobby at home and sharing the things I am learning from my experience with you.

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