sick discus! tried everything please help me

Question
Hello, I'm writing to you in complete desperation. I have a 75 gallon fish tank containing 7 3 inch discus fish (different types of variety)After adding in a weather loach that had some  white "strands" growing out of him (girl friend gave it to me as a gift didn't know it was sick) All my fish have become extremely sick. My discus especially (most important fish to me) all seem to have this white thing on their eye thats growing on it. It starts off as this little bubble on their eye its white and just begins to grow and completly cover it.

Here are some pics: http://www.discusforums.com/forum/viewtopic.php?t=15994
(where I posted for help)

As you can see it starts off as this bubble but later proceeded to grow and swallow up the eye. And its spread to everyone in the tank. I keep up with my water changes, tried  medicine (Furan-2) which helped a little bit but then did nothing. I'm completly out of ideas and have already lost 1 elephant nose, 2 upside down cats, clown loaches, my pleco (he also had fin/tail rot when he died) And I just don't understand what its all from. Please help me,

thanks Daniel.

Answer
Hi Daniel:  What you have described sounds like a type of fungal infection.  I am not sure what your tank temperature is but I would raise the temperature to about 86 degrees... this is ok for the discus but may not be for whatever else you have in the tank.  Add aquarium salt to the tank per its instructional label and begin a tank treatment with Tetracycline to help with the fungus.  please keep me posted... dave