Using Medications With Discus Fish

Healthy discus can carry a parasite without obvious symptoms. When stress occurs, the immune response drops, parasites can flourish. Stress can occur from shipping, temperature fluctuations, pecking order fighting, poor diet, and poor water conditions and wrong type tank mates. We recommend using a small quarantine tank for new arrivals. Fish purchased from pet stores, amateur breeders, club auctions and especially Internet auctions can be cleaned up before introducing into the main display tank. This is especially true for other species of fish you plan to add to the discus aquarium. Professional breeders, who utilize professional health screenings, offer much better opportunities for healthy stock. It is not advisable to move sick fish to a hospital tank. It causes undue stress and the whole tank should be treated, since all it’s inhabitants were exposed to the illness.
Discus problems can be divided into three categories. One is environmental. The best solution for this situation is to move the inhabitants into another aquarium if the situation is critical. Then identify the problem and correct it. Several times a year we hear from folks who have an air borne problem, such as hair spray, or spray paint or varnish which was used in an area near the aquarium which kills the filter bacteria and causes the tank to “crash”.
The other categories are parasitic and pathogenic (bacteria and viral) infections. Parasites by nature do not kill their hosts. To do so would cause their demise. However, in a weakened fish they can multiply and get out of hand. Also, parasites on a type fish that does not have an immune system accustomed to that particular parasite will not keep the parasite in check. Frequently the wound caused by the parasitic invasion becomes infected creating a dual problem. Bacterial and viral problems must be addressed immediately. Bacterial infections can kill quickly. Viral infections are chronic diseases, slowly debilitating the fish.
The key to having healthy discus is keeping the water parameters correct (within the no stress zone), providing regular water changes and an adequate diet. Mixing Medications Unless you are absolutely certain what you are doing and why, never mix medications. You can overwhelm the fish and possibly kill them. Some meds interact with others creating a deadly situation. For this reason, when using some meds I recommend removing any trace of it through carbon filtration. Carbon in a filter bag can be placed into any inexpensive hang on type filter. Just do not forget to remove it after 3 or 4 days. This is the only time I advise using carbon in a filter on a discus aquarium.
If I was reading this, and I am reading this as I write it, I would want examples. What substance becomes deadly when mixed with a certain substance? Here it is. Praziquantel is a slow, time released substance. However, if it comes into contact with formalin, it melts and presents 100 percent strength. That kills the fish as well as any plants and the all important nitrifying filter bacteria. So, run carbon any time formalin is used to remove all traces of it. This is only one example, there are others.