Fantail and pom-pom goldfish

Question
We have a 65 gallon aquarium.  Over the past year we have lost 2 black moor goldfish, and 2 large fantails.  We have one large fantail and a pom-pom goldfish left.  They are 4-5 years old.  They both sit at the bottom of the tank all the time, except when feeding.  The fantail has red streaks in his tail fin and I keep finding large pieces of fins on the bottom of the tank.  The pom-pom is covered with warty-looking growths and his fins are disappearing also. The tank is clean, 70 degrees, air-bubble wall, aerating filter. We have had to turn off the power jet as the fish seem too weak to swim against the current it makes.  I thought fin rot, but the fin parts are just gone, not dark or rotten looking - any ideas?  I will be happy to give more info if necessary!  Thank you!

Answer
Susan,                                                       It sounds like septicemia, I would add abroad spectrum antibiotic like tetracycline. You should check your ammonia levels.Does your filter have carbon.Take it out while you are medicating. 7 days then 35% water change and new carbon. High ammonias can burn the fins off. It cause alot of physical damage.  I would check my ammonia levels first. If they are high. Do a 25% water change now. Your tank is established and was not too over loaded unless they were really big. Blackmors out of all goldfish are susceptible to everything. I always recommend at least 20 gallons per goldie. They grow large and fast..... So lets get these guys ok and add one more when its fixed and keep it at that. Good Luck , Tina