Although most internal parasites in discus fish may not cause serious threats, you have to remember that these parasites can eventually grow uncontrollably, which can cause serious problems for your fish. A symptom of discus fish having internal parasites is that they may produce white feces. Emaciation can also occur and is also considered as a common symptom of internal parasite. Also, you should remember to provide an area for them to lay their eggs on. This can be a slate or a vertical structure where discus fish are known to lay their eggs in. The water temperature, acidity, and hardness should be stable enough and it should mimic the water in a discus fish s natural environment. You may already know about the nitrogen cycle. You need to consider the fact that this is very important whenever you intend on keeping any kind of fish in a fish tank or aquarium. If you don t know anything about the nitrogen cycle, then you may want to cancel your plans on keeping a Discus Fish. You have to remember that Discus Fish will not tolerate ammonia or nitrite in any amount. If the fish is passive and doesn t take interest of the new food available, this may be a sign of unhealthy fish. The fish you buy should eat the food or at least take interest in them. If the keeper says that they just fed the fish, then you should look for another place to buy a Discus Fish. As much as possible, you should buy an adult Discus Fish. Adult discus fish should only be fed twice a day. Don t be in a rush. Be patient. Breeding fishes doesn t happen overnight, just keep on trying. And lastly, don t forget the obvious; you will need a female and a male discus fish. Try to learn how to spot the gender of your discus fish, this way, if you want to start if with just a pair, you will be able to see if they are indeed of the opposite sex. Getting a discus fish in groups will also ensure breeding, which will eventually increase the population of discus fish in your aquarium. As you can imagine, having tiny discus fishes swimming around your aquarium is a very rewarding sight. In their natural environment, discus fish are known to be grazers.