disease I thought was ich, maybe not?

Question
I asked a question of another expert yesterday about what I thought was ich on my platy, but she made me think maybe I don't have ich after all.  One of my mickey mouse platys got white patches on the tail and somewaht up the back of the body.  I thought this was ich, so did a partial clout tx last Sunday, got nervouse, changed the water that night then went with heat and salt method.  Thursday my chinease algae eater and a mm platy fry (tiny deformed one with bent spine)both died. Until that they had all looked so healthy! The adult platy with the white spots was listless the first day, but now seems fine. I did notice he had a patch of white on his nose toward the beginning.  That since went away and now he only has a few spots on his tail left. Thing is they don't look like salt sprinkled on him.  I had another platy many months ago whos fins started deteriorating and she had spots that turned into white patches as well.  I treated with maracyn and that fish never got better, dying about a week after.  I had been on vacation so her condition was far worse when I found it than this episode. I wonder if what she had went dormant and when I did a major cleaning of algae off my tank, when everything was stirred up, it came back out?  I did that last Saturday before I noticed the spots on my platy.  

The person I talked to yesterday said to stop the salt and try a broad spectrum treatment.  I wanted to ask a follow up and see if she had any ideas about what else I may actually have in this tank.  Should I use maracyn again or something else?  Surely appreciate all ideas I can get.

Thank you,
Kim

Answer
Hi Kim,
The white patches remind me of fungus. Or a Columnaris infection more likely. Here is a good article with pictures describing this illness and treatment-
http://www.fishjunkies.com/Diseases/columnaris.php

And here's the fungus photo and treatment-
http://www.fishjunkies.com/Diseases/fungus.php

Its always possible the columnaris infection or fungus infection could be resistant to the medication you were using. I'd definitely try something else and treat with every day 30% water changes while adding a new dose of medication each time after every water change. (This wont harm your fish).
I've always had good luck with any of Mardel's products. Salt is also a good idea along with medication treatment.

Best of luck and I hope this helps!
Karen~