I had an infestation of ick in my 75 gal that has rainbow fish (dwarf neon and boseman), kuhli loaches, goldfish, neon and diamond tetras, red tail shark and assassin snails. I bought the neons and loaches at the local big box store and a few days to a week later I started noticing the dreaded white spots... Started to slowly (over 3-4 days) change the temp from 77 to 87 or 88. At the same time I started adding salt a couple times a day, about 1/4 - 1/3 cup at a time, already dissolved. The total amount of aquarium salt was about 1.5 cups for a 75 gal. That's about a tablespoon per gal. I also was dosing with API stress coat+ about once a day or every other day, and melafix as recommended to eliminate any secondary infections.
Before I started treatment I had a couple of fish die, maybe 2 or 3 over a 3 day period. Since starting I have not lost a single fish and they actually seem to be more active and healthier looking. I still have the tank currently at 88 and have not changed the salt concentration... Haven't seen any sign of ick for about 4 days, but am waiting a bit longer to make sure it's eliminated completely.
Just saying what worked for me. Fish are doing well I think because I was slow in changing the temp and adding salt. Giving them time to adjust I am sure saved more than a couple of fish as opposed to the "dump the salt in and change the temp, the weak fish will die and the strong will survive" method. Especially with the more sensitive fish. The tank is also fairly heavily planted and haven't seen any plants hurting. I have vals, bacopia, swords, wisteria, ludwigia, and grass... All are doing ok if not well.
I am looking forward to lowering the temp a bit and decreasing the salt to reduce the stress on the fish, but I'm happy with the outcome of the treatment and would highly recommend it to anyone for getting rid of ick.