Hi,
I've got 8 (I used to have 10, 2 lost to sickness) angelfish in a 100 gallon tank. I don't have anything else in there, because they ate the plecos, so I didn't dare trying to add anything else.

They do lay eggs every now and again, which I artificially raise my selfe as a hobbie.

They are very aggressive, especially when they find a spot to lay their eggs.
I have had them for about a year, and I wouldn't say I'm the smartest about fish, but I have had smaller tanks in my life with easier fish (guppies, bettas, goldfish etc...)
These guys have been really, really healthy! then I went on a trip, and my dad was caring for them.
when I got back, one had popeye and one had a large cut by it's gills. these two did not eat, and starved. so now I have 8.
they all have some torn fins, some have similar cuts by their gills (where the muscle is sticking out), some have had little cuts, which healed fast.
I've been treating them with melafix, which helped. then I ran out and tried maracyn-TC fast dissolving powder. that didn't do any thing but turn the water yellow, thick and foam on the top, which made feeding hard!
I've been doing water changes to get the out of the tank, and started adding more melafix.

I'm getting worried because one of the fish, now isn't swimming straight. he's going in a circular motion, like cart-wheels. (to the side)
so when I fed them, he couldn't get to the food and lost interest!
Please help me! I don't know whats wrong!
I clean their water 1-2 time's a week on a regular basis.

a pair layed eggs 2-3 days ago, and some are cleaning the slate, and will probably lay eggs in a day or two, while some of the fish are half dead!

What could I be doing wrong? I know the fins are torn because of aggression and lot's of fighting. I thought the cuts by the gills where too, but things are really strange.

Any ideas what could be causing this? or how I can stop it before I loose the cart-wheel fish and the others?

Thanks for reading, any tips or ideas appreciated!!