Featherfin Skin Problem :(

[Ashi]

Hi,

I have a large featherfin cat, I have had him for about 6 months now and have never had a problem with him.

A few weeks ago I noticed he was (only very occasionally) quickly flipping over and rubbing himself on the wood in the tank. He stopped doing it after a day or two, but I read up about this kind of behavior and suspected it may be Ich. I kept a close eye on him and when I noticed him repeating the behavior started the heat treatment in my tank, although without aquarium salt because I fear the effect this may have on catfish.

Since beginning to raise the heat I have noticed a very small hole in one of his bottom fins, and a patch of what looks like silvery damaged skin that appears to have grown overnight. I am now wondering if Ich is the correct diagnosis.

I am very worried because I am very attached to this fish! Please help!

I am trying to attach images now.

 

[Ashi]

Here are some images of the affected area

 

[Ashi]

My tank is 170L and it has been set up for about 4 months (we did a tank upgrade a few months after getting the catfish but we used as much of the already cycled water as we could in the new tank).

It is filtered using a large filter and aerator, usually with activated carbon although this has been removed for the treatment of possible Ich. I have also started doing daily 25% water changes.

My catfish eat sinking shrimp pellets and the others eat small floating pellets and occasionally bloodworms and sinking algae pellets.

Other fish in the tank are 1 Julii Cory, 1 Flame Gourami, 1 Congo Tetra and one Silver Bala Shark, all still small, and 5 guppies. All these fish have been added within the last month, although all are healthy and happy.

 

[Ashi]

He also now has a red mark above his gills on one side that looks like a sore... Please, someone reply!

 

[Ashi]

I have figured it's not ich and am turning the heat back to normal, although my featherfin is still flashing and now a guppy is too. I am not sure if I have set something wrong on this post but nobody is replying....