Acei With Open Sore

Hi. I have been battling some infection / parasites for a while now in my cichlid tank. It's a 75 gal MalawI tank, I hve aceis, labs and rusties. It started with what looked like ich, so I treated with super ich cure, that didn't work, changed to rid ich plus, then , then course of erythromycin. I continued to have issues, like sores and spots, lost some stock. My last three week treatment was with sulfaplex, and finally it seemed like it cleared up. Now, a week later, I see spots on them again, jst a couple. And my aceI has a sore on his side, started as a scale lifted up, now clearly a sore. Took carbon out again, and went with melafix . I have ammonia spike after sulfaplex, went to 4ppm, I put a fake plant from my other tank to reseed the bb, and with some water changes it went down to 1 ppm. Nitrites are 0, nitrates 10ppm, ph 8.0. I'm at the end of my rope with this. Although it appears different this time, before they would stop eating, have breathing issues, hung head up in the corner, get bullied and beaten up (not in plain view, but the results looked like it, they would end up with huge patches of missing and sores) . What am I missing? What should I do? Right now I have one aceI with some white spot at the base of the pectoral fin,one aceI with sore on his side,and since I'm really jaded by all he fish losses and illness, I question every tiny mark on them. Also, I see one that's resting too much and keeping away from others, worry about him too. And I netted one with the sore last night and gave him a 1% salt bath, he stayed there for 1 hour. He's not worse today, for sure, maybe some improvement, maybe not. They are eating fine, btw. Thank you

 

Is there still aggression in the tank? Loss of scales can be a sign of agression

 

He's the more dominant male. There is some very low key aggression, I believe. No one right now is missing scales, except for the sore. Those pics are from today. Not the best, I can try again with camere. My phone isn't very good for that

 

Is this sore the same as the outbreak you had last time or is to completey diffent?

 

It's completely different

 

I took some videos of him, trimmed it to an allowed size, but now I get the mesage that the extension is not allowed. Can't seem to figure out how to post video, anyone can help?

 

So fast forward a week later, sore have closed and just a slight mark left on his side. Although I see some what appears to be scratch marks, whether he's too big for caves he's trying to get in or what? I don't see anyone scratching. Still slight issues with other aceI fins. I guess I will continue melafix a little longer. What concerns me, is ammonia. Still reading 0.5 - 1.0 ppm. Nitrites 0, nitrates 10ppm. PH 8.2. Why do I still have ammonia? Is it normal for cycle to take so long?