It is true that discus are not for beginners. They will fall ill, lose apetite, show signs of black body...this means that the water requirements have not been met. It is the demand for good water quality that poses challenges to beginners. They need soft and acidic water. Discus are the best fish I have ever kept and I never get bored and tired of them.
Discus is truly the king of tropical fish! There's a variety of colours out there and they only show the brightest colours when looked after well. These fish require soft acidic waters with a low pH of 6.5 - 6.8. When buying a discus, it is best to buy the palest (not dark). This suggests that it is healthy and free of stress and stress related diseases. Also bear in mind that the discus cannot be kept with it's cichlid mate the Angel. This is because the Angel carries a parasite wich isn't harmful to Angels or other fish, but VERY harmful to Discus. When purchasing one of these kings, the customer should insist that the bag in which it is transported be covered with newspaper or anything covering the sight of the discus! This will lead to a less stressful adventure for the discus. It is even advisable to add some anti-stess to the transporting bag. Float the bag in your aquarium for at least 30 minutes then add some of the tank water and float for another 20 minutes. For the first day the aquarium lights should be switched off, and only feed the folowing day. Don't get stressed when the discus doesn't come out or act like it's hating you for at least 2 weeks. Tank mates include harlequins, cardinals and rummy nose tetras.
I would never recommend discus to anyone who hasn't learned a great deal about them. Personally, to own and treat a discus well, you must have had fish for a few years and dealt with South American fish before. These fish are very picky and require perfect water quality. When I first started with keeping fish, I wanted to get discus, but I waited and I'm glad I did. It is only fair to the discus fish that you wait until you have enough expierence to care for one. Don't be selfish and just get them without doing the proper research and having a great deal of experience, because chances are you will kill them. It is unfair to them. Also, when you get discus, be sure to buy many different types of food (color bits are really good for them). I don't feed mine brine shrimp at all, I've seen very negative results from a breeder. Also, I watch them for at least 1 hour a day to make sure that they are eating and acting all right. They are so sensitive! Good luck!
I have two discus in my 175 L bowfront tank, along with clown loaches, rainbows, angels, black ghost, elephant nose, and cory cats. I have yet to have a problem with these fish. I had the smaller one first, then added the larger one about four or five months later. My smaller one loves his tank mate. My pH is right on target, they eat very well, and enjoy being with my other fish. I have had discus before and had problems then, with one of them keeping the other in the corner and not letting him out. But things are great now. I recommend to others that they buy two or more at the same time, or hopefully buy a small one first and then come across a bigger one if so you choose. Just so one doesn't bully the other. You will truly enjoy these fish's personality and characteristics. BTW, it is recommended for almost all fish to have plants in the tank, but definitely have some for discus. At night after the lights have gone out, they will prop themselves against the plants to do a sort of fish sleep. Their eyes are of course open, but their bodies are almost limp, and if you don't know any better you would swear they had died! Just a word of precaution! Enjoy!
I am 15 and have been keeping discus for about 2 years. Currently I have only 2 discus, due to lack of money. Eventually I had to separate them, because of one picking on the other to the extreme to where I couldn't stand it. After separating them the one picked on has been doing much better, but the other seems scared and sits in the corner, unless he can't see me. This problem will be fixed soon with the addition of about 4 more discus in a planted tank. Discus do best in a group or a mated pair, after all they are cichlids. Despite all of this, in my experience the single most important thing for discus is water quality, which means water changes of at least 20% a week. You could get by with less changes, but you can definitely see the difference in the growth rate and overall health of your fish.
In my experience, discus are no more difficult to keep than angels. I've been keeping them now for nearly 8 years. However, there are a few important points to take into consideration. Make sure you start out with healthy fish. Don't buy any fish that are thin looking or dark. These are signs that all is not well and you are probably buying a sick fish. In my opinion, temperature is very important. Make sure you keep them within their preferred temperature range and don't be tempted to keep them at lower temperatures. Discus keep healthier if kept in their preferred temperature range. Don't keep them with large, fast moving fish which will stress them out. I had two silver sharks in the tank once which, although they didn't hurt the discus, they were just too quick and were stressing them. I removed the sharks and the discus settled down and got their colour back again. With regard to the controvercial subject of discus and angels living together, I have never found this to be a problem. Most angels for sale now are tank bred and therefore are much less likely to carry parasites. Wild caught fish might be a different story. I do prefer to keep the veiltail types with discus rather than the standard finned ones, as the veils move slightly slower and often seem to be less aggressive. Many people are just afraid of discus because they have heard they are really difficult to keep. I was afraid to try them for a long time, but I'm glad I did. They really aren't that difficult to keep.