That's hex the first round of treatment didn't get it. Do a large water change 50% dose with salt at 1 tablspoon per 5 gallons soak food in metro for about 15-20 mins and feed to fish. Do another course of treatment. It can be stubborn at times. I'm trying to help you save your fish, I'm not a doctor so you can use what I say or not at your discretion.
How are the rest of your water perameters? Have you cleaned your filter recently? Are you vacuming your substrate with every water change? How old is the Metro you're using?
Edit: Do another complete round of treatment, with the metro soke the food in one tablet and feed it. Keep an eye out for any sign of a secondary infection or fungas the salt and clean water should help with this.
Yeah I really appreciate your help,I have zero experience with this!
I have been following your advice to the letter, Metro food: 1 x 400mg tablet, crushed/powdered, add 1 teaspoon of seachem garlic guard, then about 100ml water, soak for 15 and drop the lot into the tank.
3sulphur, as you directed also, with water changes at 50% per 3 days
Poo hovering daily