Need Help Fast!

[fishlore101]

I just noticed this on my common pleco. On his left fin there is a blister like growth or something. I already have coppersafe in the tank that was put in two weeks or so ago. I have added more water (changed the water.) Should I put some more in it? He stays in a cave with a lace catfish and chased my pictus catfish out of the cave but they really don't fight. Here are some pictures. It looks like a big blister and I don't know how long he has had it. Sorry the pictures are blury. What could this be? I don't have a hospital tank. Everything in the tank seems to be normal. None of the other fish have this.

 

[liv2padl]

"scaleless" fish such as loaches and plecostomus have a very difficult time with medications. copper is notoriously aggressive and sensitive fish should be treated with other less stressful drugs. if this were my fish, i'd remove the copper thru water changes.

what are you using copper to treat for and why has it been in the tank for 2 week already? have you seen no positive results yet?

 

[fishlore101]

I just added new fish and I put coppersafe in the water to treat anything that they had. I am going to do to a complete water change tonight and keep an eye on my pleco. I just don't know what this could be.