Out of all the freshwater tropical fishes you can find in the hobby, Discus are by far some of the most colorful and often captivate the eyes of anyone walking past an aquarium full of them.  With such beauty, they've gained a lot of popularity over the years.  Though there are only four Discus strains that occur in the wild, through selective breeding over the years, many "man-made" strains are now available in a variety of colors and patterns.

First off, with just about any other fish tank, regular tank cleaning and water changing is mandatory.  But even more so for Discus.  As a very sensitive fish that isn't tolerable of fluctuating water conditions, Discus fish need extremely good water quality.  

We've kept Discus for over two decades, ranging from sources that come from in South America to farm raised Discus from Southeast Asia.  Using a good mixture of Reverse Osmosis (RO) water and tap water will create ideal water conditions for Discus.  We alway use 50% RO water and 50% tap water, this way it allows the Discus to adjust easier.  
Investing in a good RO filter is ideal.  The RO filter will eliminate 99% of the minerals, chemicals and nutrients that are normally found in tap water.  

We always have the pH level of the water within 6.5 - 6.8, never above or below.  Anything too far outside of that range will make them stress out and be prone to sickness.  Use Discus Buffer or Neutral Regulator to keep the water pH within the ideal range.  We highly recommend having a pH monitor around as well (digital is better).  This way, you can frequently check to be sure the level is ideal for the Discus.  For hardness, it is ideal to be between 1-4°dKH.

Water temperature needs to be between 82-84 degrees Fahrenheit (28-29 Celsius).  
Be sure to change the water at least once a week (along with cleaning the tank).  Only 10% or so of the water needs to be changed.  This ensures the water quality stays pristine.  A good quality filter system with a range of media is a must.  But do not use one that is too strong as Discus come from an environment where the water is relatively calm.  This will give your water and tank the optimal conditions.  We recommend a good canister filter, though a good quality hang-on filter with enough media inside will suffice too.

Though optional, a UV sterilizer is also great addition to keep your water conditions pristine.  There are many mixed feelings amongst Discus hobbyist but from our personal experience, it doesn't hurt to have one and will help in keeping algae and disease inducing bacteria at bay, helping your water stay clear.  People worry that the good bacteria will also be killed off, but your biological bacteria within the filter will be safe and the water chemistry will still stay stable.  A canister filter with a built in UV sterilizer can be a great option if you don't want to install additional equipment to your Discus tank.  One filter that we use for our own Discus tanks is the AquaTop CF400UV 4-Stage Canister Filter (the CF500UV 5-Stage is great as well).

Having plants is a good addition, along with driftwood .  These are optional but live plants typically help filter out the water, along with giving the tank some great aesthetics.  Driftwood helps to keep the water soft (and looks great too).  

If you want to keep tank mates with your Discus, some non-aggressive fish will do the job (particularly Cardinal or Neon Tetras).  Corydoras cats are great too!  

Do not let these requirements stop you from keeping Discus.  Once you get the hang of everything, these routine tasks will only become natural.  The beauty and joy of Discus keeping will outweigh the hassle of up-keeping!

Let us know anytime you need additional tips or advice on keeping Discus (or other tropical fishes too)!

Until next time!

-Roger
Pet Zone Tropical Fish - San Diego, California