Discus Fish

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 Keeping Healthy and Happy Cichlids


The Discus fish is a chiclid native to the Amazon Basin. Discus, in nature, fall into three species, common discus, The Heckel discus and the tarzoo discus. The discus derives its name from its circular shape and is about 8-10 inches in length and height when it is mature.

Highly social they form large shoals in their native waters. This is unusual for Chiclids. They have very advanced social behavior one of the things that makes them so sought after as aquarium residents. It is important, when starting out with Discus, to remember this. Always buy a group of fish right from the start. They will be happier and healthier, and you will get a front row seat for their charming social interplay.

Okay so I'm going to buy Discus, how big a tank do I need? Obviously, you have your own limitations of space and budget, so lets look at what the fish will need. If you are thinking of a display tank, it should be no smaller than 4 feet x 18 inches x 20 inches. This is a minimum size but surface area of water is the key here. Your tank can be any size you like but fish need oxygen and the means surface are of water to air is crucial. Discus tend to do better in deeper tanks and size matters her because the larger your tank the more stable the water conditions are going to be. If your thinking of breeding then your minimum tank size should be 5 feet x 1 foot x 1foot.

Discus Fish tend to be shy and tend to hide if they are not completely comfortable in their surroundings. It is important to locate your aquarium away from windows that let in noise and away from doors that see a lot of daily traffic. The tank should be somewhere that has a stable temperature so not near any heaters or air vents. It should be out of direct sunlight as this will help to keep the algae growth down and minimize the temperature variance on sunny days. Again the deeper the tank the better, this prevents the Discus from getting spooked by movement from above. Position the tank to provide the most stress free environment for your fish that you can find. This will allow you to enjoy your fish more and will increase their hardiness to disease. STRESS is a fish killer!

Design a Tank

Use a layer of fine gravel for the bottom of the tank unless you are breeding in which case you can leave it clear. If you are planning to use real plants in your tank then you can get some excellent selections compatible with Discus, mail order and online. This will probably work out cheaper and you will get better quality than most aquatic shops supply. In breeding tanks either leave out plants altogether or use one or two in pots.

You can decorate tank with rocks and driftwood. Driftwood is suitable for discus as their native waters often have roots and driftwood where they find shelter. Rocks should be checked for any metal ore and contaminants. Also try and keep rocks of a similar color and texture, preferably from the same source.

Discus Fish require excellent water quality, your filter is the key to this.

There are basically three types of filter:

  • Mechanical - using a physical filter medium such as a sponge. It is important to never clean the media in tap water. This filter must trap debris and solid biological waste to prevent the clogging and saturation of the biological filter.
  • Biological - Beneficial bacteria which live in porous material . They convert fish waste, mostly ammonia, into nitrites and eventually into nitrates. When cleaning filter media you should rinse the medium in tank water from water changes, not tap water. This will help keep the biological filter active.
  • Chemical - This stage of filtration is controlled by you. You may wish to add carbon or peat to the filter. Either to absorb impurities, or alter the chemical balance of the water. This is sometimes topped off with a fine wool pad to polish the water as it returns to the tank. Activated charcoal is used to removed medications and dyes from the water and peat is often used to soften it

The canister type filter system is the best for Discus it allows a large area for the biological medium. It can be any size as it is installed outside the tank, and it can be maintained with the minimum amount of disturbance to the fish. If you are setting up a breeding tank then a simple sponge filter, with an external air pump, is probably your best bet.

The quality of water in your aquarium is the single most important factor in keeping you Discus healthy and happy.

Adjusting pH, by chemical means, or the alkalinity/acidity of your tank water is extremely tricky and best left to experts. Many Discus are tank bred and do very well in hard alkaline water. You can buy a simple pH testing kit from your local aquatic supplier. Display tank should have a pH of 6.5 – 7.5. For breeding purposes the pH should be 5.5 – 6.5. If greater acidity is need try adding peat to the filter medium this will gradually reduce the pH.

'Hardness' of water can be a problem in extreme cases a little peat in the filter and some driftwood in the tank should help correct this. Essential fish need to be acclimatized to your local water source.

For a full scientific explanation of water hardness and alkalinity go to: The Advanced Aquarist.

Discus requires slightly higher tank temperature than most freshwater tropical fish. This has to be borne in mind when procuring plants and other fish species to share their home. The temperature of a display tank for Discus fish shoulb be 27.5 to 29°C and about 30 to 33°C for breeding.

Discus Fish should have perfectly round bodies with small bright eyes.They should be alert and come to the front of the tank. Do not choose overly shy or inactive fish. Make sure they are breathing easily out of both gills and that they are free from genetic abnormalities such as hook mouth.

Talk to the dealer and ask him questions, ask if you can see the fish feed, most will let you. Healthy Discus will respond quickly to food. If the dealer declines, walk away. If he wants to sell the fish he will do this for you. Ask the dealer how long he’s had the fish, if less than 2 weeks be careful as they haven’t been quarantined long enough. Did he breed the fish or did he import them, if the later where from? Does he know if they have been subjected to any medications or de-wormed? These are all common questions which he should know the answer to and it will provide you with a good background as to the fish’s history and the dealer’s competence.

Take a look at the bottom of the tank, healthy Discus fish pass feces regularly and their waste should be black. If you see signs of white or clear feces it is reasonable to consider that some of the fish have an internal problem such as intestinal worms, and so should best be left alone. Always ask what sort of water conditions the fish are in and if possible write it down. If they aren’t the same as yours go home and get them right. If you want the fish put a deposit down so the dealer will keep the fish for you and this also give you the opportunity to keep an eye on them for another week just to make sure they are healthy.

Try to get fish that are medium sized, adolescents. These are easier to adapt to new water conditions than larger more mature fish.

So what should you keep with your Discus fish? You can keep any peaceful, slow moving fish with discus, so long as they don’t dominate or out compete the discus for food and space. Different keepers have widely varying opinions on the subject. However, if you have a display tank then you want to make it look nice and have more than one species, I recommend you have a large shoal of small tetras like neon’s, cardinals and rummy noses.

Discus need a varied, vitamin and protein rich diet. Any top brand fish flake will provide them all of the nutrition they need.Discus Fish prefer their food mid water to bottom so soak and squeeze the flake first.

Variety is the Spice of Life! Periodically add other live food to your fishes diet to add variety and ensure they are interested feeders. Brine Shrimp and Bloodworm as well as freeze dried variants will keep them on their toes. Always go for quality. Low quality fish food can cause constipation and bloating both serious problems for aquarium fish.

As a rule, feed less, if you’re not sure. Discus Fish are grazers and pick at their food slowly, so allow them five to ten minutes to eat well.

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