Discus Fish Water

White butterfly discus fish

Probably the single most important factor in keeping Discus is water and its quality. There is lots of information out there but for the beginner, I think it can be confusing and a worrying factor in Discus keeping, it need not be honest.


The single most important factor (if the tank is mature) is PH as long as the pH is on the acid side of neutral, between pH 6.0 and pH 7.0, your Discus will be quite happy.

Stability of Ph because of ‘soft’ water can be an issue for the beginner and as such until a little is known about the interactions of calcium hardness(Kh) / General hardness (Gh) on the acidity of the water(Ph) staying with water of 12 to 15 Gh and 5 to 7 Kh should give you the stability of Ph and happy discus.

Nitrate, Nitrite & Ammonia

Ammonia (1st stage of the nitrogen cycle) is a killer this is the waste products from your fish and they are swimming in there own excretions. These must be maintained at 0 at all times or your fish will suffer and probably die.

Keep an eye on these levels when adding new fish to your aquarium whilst the biological capacity of the filter catches up with the increased load.

Nitrite (2nd stage of the Nitrogen Cycle) is a killer and levels should also be kept as low as possible. This can be achieved by frequent partial water changes and or encouraging good plant growth.

Nitrate (3rd stage of the nitrogen cycle) levels should be kept as low as possible (below 25ppm ideally) but is not as toxic as Nitrite and ammonia and won’t kill your fish overnight & quite high levels (above 100ppm)

Heavy Metals

A heavy metal filter, (sometimes called metals) which consists of a pre-filter pod, carbon block pod, and a CBR2 pod will remove almost all compounds that will harm your Discus fish. It will not however remove hardness.


If you live in an area with tap water which as a general hardness (Gh) of over twelve degrees, a reverse osm

Both Metalex and RO units will require periodic replacement of the cartridges. The frequency of cartridge replacement depends on the levels of contaminants being removed from the tap water and the volume of the water being processed.


If algae are or become a problem it’s worthwhile testing for phosphate which can be introduced in the food you feed fish. High phosphate levels can again be reduced with partial water changes which are by far the best method as you will remove other things like nitrate as well.

You may also use a proprietary media like Rowaphos, placed in the filter this will remove the excess.

2 thoughts on “Discus Fish Water

  1. Aloke Chatterjee says:

    Attention Mr Sanjoy Khandala. I am watching all of your videos in Ytube and other sources es. Also listening the lecturers of yours, your son’s, wife’s. I need to clear you first, that I am a hobbyist . Keeping fish in my home for my personal hobby. I am belonging from Kolkata. In our area there are so many sailors of discus fish, ornamental fish. Most of they claiming that they brought from Malaysia IP discus firm, Mark Tann, Na Discus. And sodo. Even they demand that Your name Mr Sanjoy Khandala is my friend from Sams discus. I also bring some of Discuss 3″-4″ from them. But sorry to say mortality rate is 100%. And I don’t know why? I trying to know and acquired knowledge more and more from different hobbyist and expertise. But I fail to do so. I stopped keeping ornamental fishes since last 2 years. Now again I am interested to keep fish from a good and trusted professional. I have start talking with different Discus sailors. I found most of them are fraud. And they even not saying the truth. Frankly I have no ideas about new stain or colours of mutation,genetics. I know only some of wild stain. I think you are the top of the mountain of Discus in India. I thoughts why I am not talking with you before keeping Discus fish. And go to my emotional attachment with this beautiful ornamental fish. I am waiting for your valuable opinion.
    Thanking you.
    Aloke Chatterjee.
    Phn & Whatsapp 9477503718

    • Sams Discus Team says:

      Thank you, Mr. Aloke Kumar Chatterjee, for your discus fish order with us.

      I have read your comments on your discus keeping hobby and the market scenario of imported discus fishes. I think we Indians have recently started to understand the discus quality and health which is much more important. Most of the experts in discus are usually hobbyists and not from the technical background as biologists or fisheries science. (Ornamental fish subject is not covered).
      Hobbyists have been learning discus keeping and understanding their needs in a hard way, Most traders or even the breeders have an insufficient understanding of discus fish in our country and yet have been promoting the hobby cum business….some are ethical and some otherwise. Also, I can say that we have had very good helpful discus breeders in India.

      We will do our best to satisfy our hobbyist customers with the quality and health of the discus.
      Our way is to support all our hobbyist customers for their discus upkeep and respond to any problems faced.

      Thanks for your nice expression for Sams’s discus, putting us along with big international breeders names…
      Pls, feel free to call me on my nos mentioned below for any queries regarding discus upkeep.

      Best Regards
      Sanjay B Khandagale
      Sams Discus India
      87/2, Mangrul village,
      Opposite SP farm
      Khopoli-Pen road, Taluka Pen
      District Raigad
      Mob: 8999009253/8237761811

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