Whoa there. Here is the most recommended way to treat your fish (if it is indeed ich):
Put the fish in a QT as soon as possible. Over a 48 hour period, lower the salinity of the water to 14ppt or 1.009 SG (whichever you measure by). This is called hyposalinity. Keep in mind that if you don't have a refractometer, your hydrometer is most likely not accurate. Leave your display tank fallow for one month (ich has a 21 day life cycle, but it is better to be safe than sorry by going a few days more than that). After three to four weeks (four is preferable) of having the lion in hypo, slowly raise the salinity back to its normal level. At this time, you may acclimate your lion back to your display.
Note: At MOST the temperature of your display tank should be raised to 86. However, since you'll have to leave it fallow for a month as it is, raising the temperature isn't necessary. Temperatures that are too high can kill your live rock.
-lefty