Hexamita? (hole In The Head)

(Warning graphic pictures) Hi again everyone, I am getting really tired of this stupid parasite that is lurking around my 125 gallon that keeps infecting and killing my angelfish!!! Every time I get a new angel, a week or two later they start to develop pimples on their head. Some are really small and others are medium and eventually give out puss and go away, but some get huge! Depending on the severity of it and how stressed they are, it either goes away or becomes worse by swelling up so much that it pops i guess and causes a huge infection which eats away at their skin, eventually causing death. I have lost so many angels from this , including my favorite one a few days ago. This is getting on my nerves and has been happening for a long time. I just finished the second treatment for callamanus in my tank using levamisole which caused a lot of stress into the tank and I dont want to keep medicating such a large tank. Right now I have two fish, one dead (to show the infection) and one with the pimple. It's getting so big that his eye is starting to bulge. I need help I dont k ow what to do any more. I was going to dose the infected one with some metronidazole in my 5gal qt tank but every time I add a fish to that tank they have a 25% chance of living. I'm getting a 10 gallon tomorrow and im thinking about using that instead. What should I do?
Tank stock: 11 angelfish (2 new, added yesterday)
4 rainbowfish
6 giant Daniels
1 rainbow shark
Some assasin snails as well as pest snails
1 ropefish (new, added yesterday)
1 peacock eel (New, added today)

 

Maybe if you can don't stock anymore fish and tear down the tank clean it out really well with some white vinegar, rinse it well and let it sit outside for about a week. There is something in the tank and it seems like every time you add new fish they are dying and or getting sick.
I don't want to sound rude or mean, but that's kinda bad, that you know that there is something in your tank making your fish sick, but you still keep adding more fish.

Try and look at it like this....I am not sure if you have kids, but if you did would you let your child be in a room full of sick people knowing that 1 of them has something that could kill your child?

It's the same with the fish. As the hobbiest you should know that you are only making your fish sick and unhappy.

I am VERY SORRY if what I said sounded mean or rude. I just really want to point out that please don't add more fish until you figure out what is killing your fish. And if it means taking down the tank and starting all over, then maybe that is what needs to be done.

Thank you

 

I wouldn't be adding new fish with this going on, but let's see if we can get someone to take a look who has seen and dealt with some different diseases.
@CindiL

 

No I completely understand your comparison, it's just that I have no where to put such a large amount of fish that get a bit aggressive. A lot of my fish are breeders and would fight if they were put in a smaller tank. I dont know anyone who is near me who could watch them either during that process so that's pretty much a gone opportunity. Some may say to get rid of the fish, but there is no way that's happening. My angels are very expensive and I work on minimum wage so i will never be able to get where I am now on my salary again by starting over it took me years to get to what I have. I have 8 fish tanks but they are all stocked up. I could probably break down my 29 gallon for a larger qt tank but id have to find new spots for those fish which are nanos. Metronidazole had worked very well for me with hole in the head and helped me save angels in the past but the medicine is too expensive to treat a 125 gallon tank so I use quarantine tanks only. When I get the 10 gallon tomorrow I'll try to treat my silver Angel.

 

You're not in Northern Illinois, North West Indiana or Southern Wisconsin are you?

 

Petco has their dollar per gallon sale going on, if you need a cheap spare 10gal

 

I live in NJ

I'm getting a 10 gallon set up for free so s all good