Hi every1 I need some advice on which would b the best route to take for treating my fish rite now. I have done 4 partial water changes in the last week because I thot I had ammonia spike and a couple of my goldfish seem better but my 2 plecos have become worse 1 goldfish has a red sore and some skin sluffing off and this morning my albino pleco has a red sore on its belly. The 2 plecos both have tail fins that r fraying some but my goldfishes fins r ok. My black moor had a little bit of white mouth earlier this week but partial water change it went away. My question is should I treat withan chemical that will lower the ammonia and put in filter bag for helping with ammonia level or should I treat for bacterial infection? The guy at pet store reccomended e.m erythromycin. Any input is appreciated thanks

Why is there ammonia? How long has the tank been setup? What size is it? How many and what type of fish in the tank? Justr sounds like ammonia poisoning.

Its a 100 gal tank and has been up for 3 1/2 yrs

Oh and 1 black more 2 gold fish and 2 plecos

How was there ammonia? Doesn't seem like 3 Goldfish and 2 Plecos would cause it unless something is wrong somewhere. Are these common Plecos? How big are they?

They r both about 8 inches and my goldfish r about the same size I think my filter is about toast may b part of the problem the guy at the pet store said they all produce a lot of waste and ammonia can b a big issue