yes!Aside from curing your tank of ick, in my mind, ick is a stress related disease. Lack of oxygen, lack of rockwork, lack of flow, lack of proper foods, overstocking, stocking in tanks that are too small, aggression, etc..... all these contribute to stress which can lead to ick.
Some of the fish you listed should be in much larger tanks than a 75, and seems you had a few larger fish in the tank, this is stressful to the fish.
Stress leads to ick, and good fish care in my opinion comes down to avoiding all stresses to the fish. Just me 2 cents.
can u please add a pic of the tank, and a 20second video under whites plz, YouTube vid! mp4's dont work here much