Hi Kangster,
Here is the set-up: 30 gallon freshwater. Started out with 2 dolphin catfish (had them for 2 months in a smaller tank), 1 Upside Down Catfish, 1 Spotted Catfish, 1 Marbled Angelfish, 2 unknown (forgot what they are). They were fine until I added 3 new fish last week: 2 Clown Loaches and 1 more Marbled Angel. All of the fish in the tank are about 2 -3 inches in length. So after I introduced the new fish, they started dying one by one. The new clown loach died first and the other Clown is sbarely alive with fuzzy spots (ICH?). the other two dish had the spots too. Now two other fish look like they are getting the symptoms: Fuzzy spots, lethargy, lack of appetite.
The local aquarium store gave me fungal meds for the water which I added a day ago. I will get a test kit today to check the parameters as you suggested and I just raised the temp by 1 degree today. Thanks for the quick response!!