Is it Fin Rot????

[tattis]

I have a 25 gallon freshwater tank with african cichlids. Fish included are 1 Red Zebra (4cm), 1 Aulonacara(7cm), 1 Pseudotropheus(4cm), 1 Kadango(10cm) and 1 Venustus(10cm). Then tank was setup 3 months ago with only the venustus and the zebra and were doing fine for 1 month. After that I added the other 3 fish and venustus started having signs of fin rot on the back fins. It was slowly but steadily deteriorating its fins. I treated the tank with Tetra General Tonic which i supposed to be good for fin rot, but did not improved its fins.

Two months after the initial steup I removed venustus in a 10 gallon hospital tank and following my LFS suggestion I treated the fish with malachite green. Again...nothing happened. Venustus is still in the hospital tank alone and every day is getting worse with his fins (very very slowly).

My tank parameters both hospital and normal have 0 values for ammonia, nitrites and nitrates, 27 C and 7.9 ph. I change 30% of water every 2 weeks (hospital tank is changed every 1 week).

Can you please give me any ideas of what is going on??

P.S. Side fins seem OK and not affected.

[Frisckey1]

Are you adding any salts to their water?

Fin rot is more often than not the fault of a bacterial infection. If you are already adding salt for your cichlids, I'd guess you need to move to a stronger, more aggressive med, and increase your water changes...are you changing water and gravel vac'ing? The increase in water changes will reduce the bacterial load in the water. Water changes are very helpful in dealing with bacterial infections.

The thing about bacteria is it can mutate...if your first trys at combatting it didn't help or work, the bacteria may have developed an "immunity" if you will, to the meds. The new strains of the bacteria may be resistant to the meds you are using. Move to an stronger anti-bacterial med, like Kanacyn or Maracyn.

[Menagerie]

Was the Venustus picked on? The "rotting" fin may be due to stress, but often all fins are affected. Can you post a pic?

[tattis]

Unfortunately I can not post a picture right now but I will get my camera later today and do it.

The strange thing is that the tank was very peaceful for an african one. Not many fights and certainly not with venustus. I never added salt to my fish, if this can help. Also despite the fact that the fish continues to eat normally I noticed some loss of weight (sort of sucked belly).

[Menagerie]

Also despite the fact that the fish continues to eat normally I noticed some loss of weight (sort of sucked belly).

There may be internal parasites that are getting all the nutrients. QT the fish and treat the food with a powdered med that rids parasites.