They've been on daily malachite green for two weeks now, only thing missing is the maracyn 2 in the food. I've been feeding them Sulfaplex in the food for the two weeks too and dosing it in the water column. I don't have easy access to maracyn 2 or seachem focus. I could try and order them from online but so far no luck finding the maracyn 2.
I can get my hands on Kanaplex or metroplex and I think I know where to get erythromycin. Would any of those work as substitute? Gram negative is harder to find meds for.
Also out of curiosity for next time how could you tell it was Epistylis? Lots of the pictures I see of it do have some clumps but also loads of them just look like ich covering the whole body, while this one is primarily on the fins even after failing to treat it for 2 weeks now.