Hey Im new to the forum, I keep having this issue with my PN plecos. I've been searching everywhere trying to figure this out and can not find any info on how to treat it. Im worried that this is going to harm my other fish. this is the third pleco to have this similar issue.
I have a 100 gallon tank and do weekly 30% water changes. I keep the temperatures at 81-82 degrees.
I do not have a testing kit so i can not tell you what the levels are how ever once a month I bring a water sample to the local pet store and each time they just say its with-in normal ranges.
any help would be greatly appreciated, thank you.