Bacterial Infection

[Uriel]

Last Night I noticed one of my plec's had a red tail and was very stiff. I removed him from the tank and put him in a hospital tank worrying that he had been somehow bitten by one of the other fish(oscars). Researching on the internet i found out that this is apparently a sign of a bacterial infection caused by poor water quality. My tank water has never gone above 0 amm 0 nitrite 20 nitrate.

Unfortunately this morning i found him dead and one of the other plecs has developed the same condition. I've done a 50% water change just to be on the safe side. Tested the water and stats came back 0/0/10-20(before water change) so i don't see how it can be a water issue(although all web sites attribute it to this). The only thing i can think of it may have been cause by malnutrition as oscars seem to eat everything that is put in tank. even plec wafers that i put in, in the dark.

Started treatment with melafix but not getting my hopes up.

Any help anyone can offer would be appreciated.

 

[Proxo]

I've had a similair problem, lost 2 plecos and a few other fish due to it too..
I did alot of research and it all kept saying it's due to "poor water quality" but all my tests came back fine.

I did try a general tonic that is ment to "keep the aquarium healthy by suppressing background levels of fungus, bacteria and parasites."
But i dont think it done much, a few days later one of my keyholes started to look like what i think was fungas infection.

I kept the water changes up & the tank did settle back to normal and has been since..
The keyhole didnt make it though

I'm sure someone else here will have a better answer for you though