Fine Rot??

[Eve]

Nitrates-5.0
Ammonia-0
Nitrite-0
75gallons-2 400 emperor power filters
78 degrees temp

It has been running for 1 1/2 years.I fishless cycled it and my tests have always been the same.I change and gravel vac once a week 15 gallons.I have 3 bala sharks about 5 inches( have had for 3 years) each and 5congo tetras.The bala sharks fins are raggetty and the parts of the rays almost see thru.Now I noticed the congos fins are getting shorter.What am I doing wrong!I used Melafix no change then I used fungus eliminator.I am scared to use medications.They act normal and eat well.About a year ago one bala jumped out of tank but thank goodness i was in the room and put him right back.(He jumped thru a 2in hole that i had my heater in.)could he have put a disease in the tank.I added air bubbles thought maybe it would help.Does anyone know what else I could do or look for??Thank you EVE

[HanshaSuro]

As far as I understand, all those little diseases are present in the water we put in the tank, just swimming around in there. When the fishes' immune systems are low then the diseases have a chance to get a foothold. (Like how we are swimming in germs and viruses but aren't usually sick). So I wouldn't worry about how your fish got it. It does kind of sound like fin rot to me. My betta is getting over a case of it right now. It can take a while to clear up (weeks) so just keep medicating the tank faithfully with something that is safe for your fishes and be sure to give the whole dose indicated on the label. Its like taking your antibiotics, if you don't finish the bottle you just get sick again. Is salt ok for your fish? I know aquarium salt is helpful for healing rots. Good luck. (:

[Eve]

thanks for the reply. I bought new test kits to retest the water.They all came out the same.All the fish fins look frayed.What medicine should I try?I already tryed melafix but no change.I did only one dose of fungus eliminator should i try that again.I never miss a tank cleaning .I dont over feed why is this happening?? Eve

[HanshaSuro]

Fin rot usually happens when the fish are stressed. Have there been any changes in the tank that could be stressing the fish? Any bullying, moving plants around, anything odd? Its a bacterial infection that can also include secondary fungal infections so you'll probably want both antibiotics and fungicides. Treat as long as is recommended on the package for whatever you use. I'm treating my betta with something that's just for bettas, so I have no advice for brands. Anyone else out there?