I just set upm a tank in the last few months. I purchased a Sailfin tang that was covered with ich within 48 hours. It was not doing well the following morning. I purchased organic ich lquid it says you can double the amount so for 3 days I doubled the dose then brought it down to the recomended dose and also brought the temp in the tank to 80 The organtic meds are safe for crustations and such. I am glad to say that It is gone and was very succesful! about 7 days into treatment it got bad again but persistance was the key. Good luck
Armywife