Help Pls What's This On My Fish

HI I've noticed two of my gold barbs have this sore on their side and I'm unsure what and how to treat them, water parameters are 0, 0, 10, I do a 70% water change weekly, its a 165ltr tank with 8 goldbarbs 2 weather loaches 4 zebra danios 3 platys 1 plec and 4 clown fish (clown fish being rehomed in the next week, a friends tank burst and she didn't want to get a new one so I took them in), all fish acting normal eating fine swimming to front of tank wen they see me, thank you for ur help

 

Maybe some kind of ulcer. Really bad with fish diseases so I’m not sure.

 

This species does seem sensitive to skin complaints. I think the only thing you may be able to do is accept that they don't like your local water and keep another species. This is what I have done. It seemed like the perfect fish for me, but no. I have been very successful with a range of other species but not this one.

 

Thank u both, I've had them 4yr and this is the first time they have had any issue

 

Wait, this is OT but... I'm baffled on the mention of clown fish? In a freshwater tank?

 

Wait, this is OT but... I'm baffled on the mention of clown fish? In a freshwater tank?

Sorry I ment clown loach x

 

Sorry I ment clown loach x

Ohhhhhhhh. Okay. I was so confused and near the point of protest. Don't mind me ha. I don't know much about fish diseases so I'm not a help here but I couldn't resist asking.

 

Clown Loach are often referred to as Clown Fish on this forum. I should know I've been keeping them for 25 years and I've been on the forum for 10 years.