They're dying! HELP!

[feliciae]

I am having issues.
One of my Hi-fin black skirt tetras is floating around like he is going to die, and one of my angels is doing the same thing. Their fins are a little ragged (not so bad, just like they got into a little bit of a tussle with someone else) but the inside of their gills is really red, and my tetra has a white bump on his forehead that isn't supposted to be there.
I was thinking that mabye one of my gouramis committed a massacare because he got territorial, but I don't know. I have seperated the gourami, and both my angel and my tetra are in a heated 5 gallon tank where I hope to be able to fix them. They look horrid though.
HELP!
I know that it isn't an over stocking issue, I have sold most of my original fish, and I did a fish caculator, and I am at 99%. There are plenty of hiding places, and I re-organized earlier last week to switch things up a bit.
The tank is clean, Ammonia and Nitrite levels are at a 0, and Nitrate is just fine.

 

[littletankbigworld]

How large are your tanks? What fish are in each tank? I'm hoping you got rid of the goldfish and plecos because if all of those fish are in the same tank, you're in big trouble. It definitely seems like a stocking or aggression issue. Angelfish need a 40-55 gallon tank. They need to be kept in pairs, or they'll show aggression. The red gills sounds like ammonia poisoning. Did you test the water with a liquid test kit? What are the levels in each tank? The white bump could be ich or velvet, which is usually brought on by very poor water. I think you should update your signature so we know which fish you sold.