Help need a fish expert for ICH/ICK?

I would suggest stopping your current treatments and start something more effective, like malachite green + formalin (Quick Cure, Rid Ich). I don't know why the store would think the parasites were resistant to anything after only a few days. Malachite green + formalin is by far the most effective treatment, and at 86*, you shouldn't have any trouble (make sure the tank is EXTREMELY well aerated). If you have any scaleless or sensitive fish, like Loaches, Catfish (you do), Puffers, Knives, Tetras, etc, use half the recommended dose.

EDIT: Running the temperature as high as 90* (which is really about what you'd need to kill the parasites) is extremely risky for your fish. I would use it only as a last resort, continuing to maintain 85-86* temperatures.

EDIT 2: Worry about the Ich before the Guppy's fin rot-- that can wait. The treatment procedure you've taken so far is absolutely perfect, just consider using a different, more fast acting (and in actuality, less toxic) treatment like Quick Cure or Rid Ich.

Sorry to hear you are having such trouble with your tank. I recently had a break out not only ich but also a parasitic invasion - I thought it would be hard to get rid of it all but its not - I went to "petsmart" and bought a small bottle of "maracide" - it cures several kinds of infections - one dose on days 1, 3 and 5 adn thats it - then 25 to 50 % water change after that

Maracide is plant friendly and also you can leave all your filtration in place as it is recommended by Maradel, the makers of Maracide - I will also provide a web site for you to read about maracide before making this your choice

The web link is specifically for the 16 oz bottle at petsmart but they also make smaller less expensive bottles

I can easily see Obama and his environazi thugs cut off all public lands as "protected" and keep all people off. Easily. Interim Report The Task Force released its Interim Report on September 17, 2009 which was open for a 30-day public review and comment period. The single most obvious flaw in the report is the omission of responsibly regulated recreational fishing as a key activity for the oceans and the Great Lakes. This is of concern to America's 60 million anglers, whose conservation, economic and social contributions should be recognized as a key component of the policy. In addition, as a national policy document governing the oceans and Great Lakes, the report is skewed toward a preservationist policy of locking up public waters instead of one that promotes sustainable uses such as recreational fishing.

Keep doing what you are doing. You took the carbon out of your filter, correct?

I suggest purchasing an extra tank and using it as a quarantine tank. That way that will not ever happen again.

I had success with the Jungle tablets. Don't forget to use a fungus cure after you use the ich clear.