We have a 30 gallon tank with four fish, the black moor (as pictured below), an algea eater, and two fan tails. The tank has been set up for close to a month and a half and has a water heater (set to 70 degrees), a filter, and a bubbler. Every two weeks or so we empty out 1/4 of the water and add in new water which is conditioned with tetra fin water conditioner. The black moor and two fantails were showing signs of what I thought was ick, so I started a 5 day treatment for ick in which the treatment was delivered on the first, third, and fifth day. The fish were fine after the first treatment, and after the second treatment they began to hang out at the bottom of the tank (all except the algea eater, who throughout all of this does not seem to have been effected at all). The three goldfish would refuse to move unless we were feeding them. On the last day of treatment, the black moor seemed to be peeling, almost as a human would if they received an extremely bad sunburn. He was dead this morning looking like the picture below. The picture was after he had died (at most only 2 hours dead). We've separated the algea eater (who is still not showing symptoms) from the other two fantails, one who is starting to peel and the other who is still just chilling out at the bottom of the tank. Please help! I miss my black moor and I don't want the other two to die too. =(

We were treating him for ick and the algea eater won't touch any of the fish, believe it or not. He completely ignores them. And... his eyes didn't fall out... they're just obnoxiously huge for a black moor... Haha!  The second fantail died this morning as well , same thing, same look, and he was separated from the algea eater.  What can I do to keep my last little guy alive? =(

I've got a pleco with my goldies, no problems
Here, from the looks of it, this fishes' slime coat is incredibly thick. Probably protecting it from parasites or something bad in the water. How is the second fish holding up?
Now I'd be changing the water regularly, adding tons of beneficial bacteria to the water. I would recommend "fluid filter media" by EasyLife since it helps the fish heal smaller wounds at the same time. I would also treat the water with normal, medical aquarium salt according to the package since this will help against almost anything Do a 75% water change before adding the salt and leave it alone for a week, just keep an eye on the fish.
Feed the fish some anti-parasitic food as well, and DO NOT buy any more fish. Your tank is full with these three fish now.