Hmmm.....haven’t followed this thread too closely as I thought it was about Ich - but it seems to have got complicated so I’ll get stuck in now......
The “rights and wrongs” of how you’re running your tank I’ll address in a bit, but first things first........
The water quality in your tank has caused a few diseases to get a hold of your fish and multiply. It sounds like they have all happened pretty simultaneously, but the Ich was the first to become visible. Second place goes to the bacterial infection that is still killing them, and third place goes to the fungal infection you have already noticed.
Malachite Green et al, is pretty good at clearing up the Ich and the fungus, but absolutely crap at dealing with bacterial infections, which is why your fish are still sick.
I quote the following link.....
“It is important to realise that in most cases, fungal infections of fish are secondary infections and unless the primary infection - quite often bacterial - is resolved then anti-fungal treatments such as malachite are unlikely to be successful”.
http://www.fishdoc.co.uk/treatments/malachite.htm
The Jungle labs meds and the Malachite Green will have done a sufficient enough job on the Ich and the fungus for you to stop using them at this point and give the fish a break. If you haven’t used the jungle Labs stuff yet then hold off on that while I explain why........
The malachite green will have sorted out the Ich and the worst of the fungus, but it’s the bacterial infection you need to deal with. As most Bacterial meds also treat for fungus at the same time, it’s pointless using two types, and they don’t all mix well. As you have to get an anti-bacterial med anyway, find one that says it does both bacterial and fungal, and only use that one. Giving the fish a 24 hour break between meds is always recommended (as is a 50% water change to get rid of the old meds). You’ll need to treat the whole tank and not just the affected fish as it’s your tank that’s the real problem here.
So - stop meds now - carbon out - 50% water change - wait 24 hrs then new combined anti-bac and fungal meds in. As this has been going on for 3 weeks already, I would suggest you do this pretty quick or you’ll (probably) lose the lot.
(Never run carbon in your filter with meds - the carbon takes the meds out).
OK - I’m going to post this up first then get onto the subject of your tank.......