Kuhli loach white patches

[Ianvaldius]

I noticed some white patches earlier today on one of my kuhli loaches. It definitely isn't ich, but I'm not sure if it's a disease or the Kuhli rubbed against something that scraped him. I looked up the issue earlier and stumbled onto a thread where someone mentioned their kuhli loach had made it into their filter and he had some scrapes from that, so I took apart my filter and found a different kuhli alive and well inside it. So I'm not sure if this one might have gotten in it and, being a bit bigger, got scraped and decided to leave the filter (I've only been able to find three of my kuhlis at a time for the past few weeks, but I counted four this morning and then five after I opened up the filter). Thoughts? The tank is also currently being treated with seachem paraguard because I noticed some ich in my black neons. The tank is slightly acidic with a hardness around 150-200 ppm. Chlorine is at 0, nitrate around 20 and everything else at 0.

 

[JuiceBox52]

Do a large water change (75%), it is possible he got scraped or it's some sort of infection or fungus. Whichever it is water changes will keep it from getting worse or getting a secondary infection

 

[Bleeding_wings]

I know this is an older thread but my kuhli loach has the same. Did the water change help out your kuhli or was it some sort of bacterial infection?