Discus fish are tropical freshwater fish, originally from the Amazon region in South America.

Compared to other fish, discus fish are indeed expensive. Discus fish take around two years to grow. During this period, they must be kept in water at a constant temperature of 30 degrees Celsius. This requires a lot of energy (costs). They also need to be fed at least two to three times a day, which results in high feeding costs. The aquarium water for (professionally) growing discus fish is also changed daily to ensure good growth. This results in high water bills. All these factors together (high electricity bills, water bills and feed bills) contribute to the relatively high purchase price of discus fish.

It is recommended to keep discus fish at a water temperature between 28 and 30 degrees Celsius. Young discus fish are best kept at a water temperature closer to 30 degrees Celsius to ensure good growth, while adult fish can be kept at a water temperature of 28 degrees Celsius.

For discus fish, the exact water parameters are not the most important thing (what the water parameters are exactly), the most important is stable water parameters. In short, water parameters that are always the same (stable). Discus fish benefit from stability because they react to changing water parameters. If water parameters fluctuate, discus fish can become skittish, start breathing rapidly, and so on. The most important thing is therefore that the water parameters are as stable as possible. As long as they are within the following tolerance limits (the minimum and maximum that the animals can tolerate):

– Temperature (short term): 25 – 35 °C.

– Temperature (long term/normal): 28 – 30 °C.

– GH (General Hardness): 0 – 30.

– KH (Carbonate Hardness): 0 – 25.

– pH (pondus Hydrogenii, acidity): 4 – 8.3.

– EC (Electrical Conductivity): 150 – 1200 µS.

Note: with these tolerance limits, our discus fish are suitable for 95% of tap water throughout Europe. This means you can keep them in normal tap water without treating it. As indicated, the exact water parameters are not that important, as long as they fall within the above tolerance limits and the water parameters are always as stable as possible.

Our discus fish are swimming in normal tap water, straight from the tap without any additives, with the following water parameters:

– Temperature: 29–30 °C.

– GH (General Hardness): 12 – 13.

– KH (Carbonate Hardness): 9 – 10.

– pH (pondus Hydrogenii, acidity): 7.0 – 7.1.

– EC (Electrical Conductivity): approximately 500 µS.

Discus fish are kept at relatively high water temperatures. Fish and plants that you want to combine with discus fish must therefore also be able to tolerate high water temperatures. This rules out many species. In addition, other fish that are to be combined with discus fish must be calm in nature and not bother the discus fish. For these reasons, tetras (such as the Rummy Nose Tetra), corydoras, South American dwarf cichlids, small L-numbers and small algae eaters are often excellent choices for combining with discus fish. In terms of plants, these include Echinodorus (such as Amazon sword plants), Valisneria, lotuses and most floating plants.

There is no clear-cut answer to this question, as it depends on how often you want to change the water. The more often you change the water, the more discus fish you can keep in an aquarium (and vice versa). On average, we recommend approximately 40 litres per adult discus fish. This is based on a water change rhythm of 30-40% once a week. If you change the water more often, you can use 30 litres per adult discus, for example. And if you change it less often, 50-60-70 litres per adult discus is better. This applies to adult fish. Are you starting with young discus fish? Then always start with 2-3 more discus fish than you ultimately want to keep (when they are adult). Discus fish always establish a hierarchy among themselves, with the leaders often chasing away the underdogs at feeding time. As a result, leaders eat more than underdogs, causing them to grow faster (while the underdogs grow more slowly and even weaken or die). Unfortunately, this often results in the discus group being thinned out by 1-2 fish over time (hence the advice to start with a few more fish than you ultimately want to keep when you have a group of young discus). In any case, discus fish are schooling fish. This means that they must be kept in a group of at least 5-6 fish. This requires an aquarium of at least 250 litres to successfully keep discus fish.

That depends on the size of the aquarium, the number of discus fish, the total fish population and the filter capacity. The minimum is 30-40% once a week. It is even better to change the water once more during the week (when we humans spend a few hours in a small space, we often like to open the window for some fresh air). It is also advisable to change the water once more if your discus fish are shy, hide a lot, turn dark in colour, etc.

All discus fish here are fed 3-4 times a day, alternating between different foods. They are given dry food (both granules and flakes) and various types of frozen food. The most important thing is that they are fed a varied diet so that they get lots of different vitamins and minerals (I like steak too, but not 3-4 times a day, 7 days a week). Try to avoid mixing different types of food (feed them a variety, but not mixed). This is because discus fish will still pick out what they like from mixed food (and therefore still eat an unbalanced diet, even if you feed them a variety of mixed foods).

Our advice is simple: just wait and see. Discus fish need at least a few days to recover from the stress of moving and to get used to their new environment (such as the layout, lighting and water parameters). Especially for adult discus fish, the acclimatisation period can take a long time, up to 6-8 weeks maximum. During this period, they do not eat or at least eat much less than normal. This is not harmful to adult discus fish, as they have built up good reserves. Young discus fish experience less stress from the move and therefore acclimatise more quickly to their new environment. They often start eating within a few days of the move. In short, a little patience is often required.

Our advice is simple: just wait and see. During the first few weeks in their new aquarium, discus fish are busy determining who is the boss (and who is lower in the hierarchy). Once the hierarchy is clear, calm usually returns.

This is usually due to the hierarchy within the group. Discus fish always establish a hierarchy among themselves, with the leaders often chasing away the underdogs at feeding time. As a result, the leaders eat more than the underdogs, causing them to grow faster (while the underdogs grow more slowly and may even weaken or die). There is usually little that can be done about this (it is nature; in small discus groups, they always establish a hierarchy among themselves). Sometimes it helps to increase the size of the discus group (because the larger the group, the less hierarchy there is, and the more equal the chances of eating and growing). In the wild, discus fish live in very large groups (of many hundreds of discus). In such large groups, there is no hierarchy, but rather shoaling behaviour. Due to the size of the group they protect each other, feel safe and each discus has equal opportunities to eat and grow. Of course, we cannot replicate these conditions in our living room aquarium (we would need a huge aquarium), but we can take them into account when purchasing the discus group we want to start with.

It is very difficult to say without seeing and knowing the specific circumstances. Please contact us by email (info@discuspassie.nl) or telephone (+316 4664 7241) for advice. Please include the answers to the following questions (to give us an idea of the situation and enable us to provide useful advice):

– How long has the aquarium been running?

– Where exactly is the aquarium located in your home, is there a lot of light and from which side(s) (relative to the aquarium) does the light come in?

–    How many litres does the aquarium hold (or what are the dimensions of the aquarium)?

–    What is the filter capacity?

–    What kind of lighting do you use (bright light, dim, etc.)?

–    Do you use CO2, nitrate resin, aeration (oxygen pump) or anything else in the aquarium?

– How is the aquarium set up (e.g. dark or light background, what is the substrate made of, does the aquarium contain driftwood, etc.)?

– What is the total fish population?

– What is the water temperature?

– What are the exact water values (i.e. not just good or bad, but what are the specific water values)?

– Are the water values always stable?

– How often and how much % of the water do you change at a time?

– How often and what do you feed the discus fish per day?

– What symptoms are the discus fish exhibiting (e.g. dark colouring, rapid breathing, retreating behind the wood, constantly hiding in a corner, standing on their heads, etc.)?

– Do you perhaps have a photo or video?

It depends on the age/size of the discus fish and how long you are on holiday. Discus fish measuring 13-14 cm or larger are often best left alone during the holiday (maximum 2-3 weeks). Before going on holiday, slowly reduce the water temperature to 26-27 degrees (no more than 1 degree per day) and change a lot of water (at least 60-70%) just before you leave. Other than that, just leave them alone until you return from holiday (do not let others feed them, they usually have enough reserves). After your holiday, change the water again, slowly build up the feeding (do not give them food that is difficult to digest straight away, but start with some light flakes, for example) and slowly raise the water temperature (no more than 1 degree per day) to the normal level. Are the fish smaller than 13 cm? Then have them cared for (fed and possibly also have the water changed) by someone you can trust. Provide clear explanations and instructions in advance (do not overfeed, etc.).