Good grief! What are your water parameters right now? Bloody red scales would mean one thing, your deteriorated water conditions are taking its toll on the fish.
If I were you, just feed the fish and do daily water changes. Without the nutritional diet (while still maintaining clean environment), they cannot resist any health issues easily. Salt alone will not help much if you don't provide them a way to resist the parasites themselves.
I've been having problems comprehending some bits of posts every evening.lol