Ich, then tailfin white spots

Question
Hi.
We have 4 platies in a 20g tank. Two weeks ago one developed a white spot near its mouth, and another fish had sprinkles on its tail. We figured it was ich, and have been treating with salt, higer tank temp, water changes and RidIch for two weeks. We thought everything was progressing, though a week ago one fish developed a new spot on its tail that looked larger than the Ich spots. Then today there is another of these faint but larger white spots. We've been doing massive water changes daily and have two filters (one 10g and one 20g) to make sure water quality is very high. Any ideas?  

Answer
Hmm. Fungus. Not fun. Did you rememeber to take the activated carbon inserts out of the tank? They will filter out any medicine or antibiotic you put in the water, and decrease it's efficiency.

Ich is a parasite, so it takes a completely different type of chemical to treat them. Get a special treatment for fungal or bacterial infections like Maracyn or Maracyn II and see if that helps.