You can also include most peaceful and slow moving South American fish as well as Dwarf Cichlids with the discus fish. However, you just do so if the other fish doesn t compete for space and food with the discus fish. Blue and Golden Gouramis can also be included in the discus fish tank but are not recommended because they are more aggressive in nature. Tap water is full of chemicals which can be very harmful to discus fish. It may be helpful for your healthy but the chemicals can be very damaging to your discus fish. This is why it is important that you monitor the water s chemistry every time you change the water in your discus fish aquarium. In most parts of the country, chlorine and chloramines are added to water supplies. When you have finally established your discus fish breeding tank, transfer some of the water from your original tank, this will prevent your discus fish from experiencing stress in being exposed to a new tank. Don t put any gravel or sand inside your tank, this will make it easier for you to clean your tank from leftover food. Here are some points which can help you identify the gender of a discus fish. Male discus fish have thicker lips. Discus fish use their mouth to fend off any attackers. So the thicker lips are necessary for their protection and of the females as well. The male discus fish is more aggressive, they tend to come between the female and any intruder to protect the female discus fish. The big news is, most fishes, including the discus fish, maybe even more so, develop health conditions because of stress. Although fishes are fragile as compared to other household pets, they don t really just die and wither if they are kept well. And all you really have to do is make sure that the tank is clean and feed them as scheduled, which is not really all the time. The tank surface area is necessary because this is where the oxygen and carbon dioxide exchanges. So if you have 3 to 4 pairs of discus fish, a 75 gallon tank would be good enough. If you can, try to add an outside filter, especially if you have a large tank, s this will be able to help out in increasing the aeration and the filtration of the tank.