No creature would like to live in a dump. If you notice that your tank s water is getting dirty, you should change it. You should always clean your tank of leftover food. So that you wouldn t be bothered of cleaning your tank or changing the water often, you could add some sufficient filtration system, some lighting, or maintain some bottom dwelling fish to help clean up the tank. So if you plan on buying a smaller tank know and just upgrading to a bigger one later on, you may find that this would be futile. You would just be spending more in a short period of time. A small tank will just stunt their development and will stress them out. But also remember, if the tank is too big, the young discus fish can become overly skittish and can also stunt their growth. Keeping Discus Fish are quite easy to do. You just need to maintain the water quality and feed them right. Breeding them is another story. This is the difficult part. But, with some proper guidance, you will be able to start breeding Discus Fish which you can keep or you can even sell for profit. We all know for a fact that taking care of Discus Fish can get quite expensive. Unlike other types of freshwater fish that you will often see in retail chains, Discus Fish will require you to pay close attention to them in order to keep them healthy. But, you shouldn t let this fact intimidate you and scare you from owning this kind of fish. With the right knowledge, you will be able to maintain this beautiful fish for many years to come. 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. If the quarantined fish do not show any signs of illness after two or three weeks in the quarantine tank, you can introduce them to the main tank. Also, you should keep in mind that discus fish thrives in tropical waters. So, keep the water temperature in your tank between 84 to 86 degrees Fahrenheit.