[Glugdibean]

I have a 75 gallon tank setup for almost 2 years. Have had issues with high Nitrate readings but with large water changes twice a week that is down to around 5-10 ppm. There are 2 plecos and 12 cichlids in the tank. One fish that has been the most aggressive in the tank has in the last couple of days become sluggish and sort of hides in the back. The fish has what appears to be some sort of scrap on his side and we recently lost a fish that had a similar mark on him. The majority of the fish in the tank are OB Peacocks. The fish with the problem is a light blue color and we bought him with some others from a local pet store 2 years ago. PH in the tank is high because our well water has high PH and the fish have been just fine with that. Some of the OB Peacocks were hatched in the tank. We feed them once a day with large flake food and occasionally with frozen brine.
Question is how to treat the one fish. SHould we take him out and treat with aquarium salt or can we get away with treating the whole tank with salt? Plecos are supposed to not like salt.

 

[DJRansome]

I would take him out because the hiding is not because of a scrape. A scrape will heal with just clean water. Can you post a clearer pic of the wound or give a better description? Is it fuzzy? How big, what shape?

 

[Glugdibean]

It isn't fuzzy. Just appears that some scales were rubbed off. Will try to get a better picture. I could take the fish out and put in a bucket with water from the tank, but I don't have a setup quarantine tank.

 

[DJRansome]

The bucket would need a filter and heater. The scrape should heal by itself...but it is worrysome that a fish died with the same mark. Also that he is sluggish and hiding.

You could try Googling columnaris just to rule it out...with that you get patches and the fish die like happened with your first fish.

 

[Glugdibean]

The fish sometimes spends time hiding at times head down among some fake plants and then at other times it out with the others just as lively as ever. The scrap on his side seems to be improving. He is out looking to get fed in the AM and is eating well. This is a fish that was a prime bully in the tank, but has backed off from that behavior. Not sure what to make of this.

 

[Old Newbie]

The fish sometimes spends time hiding at times head down among some fake plants and then at other times it out with the others just as lively as ever. The scrap on his side seems to be improving. He is out looking to get fed in the AM and is eating well. This is a fish that was a prime bully in the tank, but has backed off from that behavior. Not sure what to make of this.

Sounds to me as if another fish has taken over the bully of the tank.