Do you have inverts or LR in your tank? If not, I would just do the hypo straight in your main tank and bump up the nutritional aspect of your feeding. Get a good vitamin supplement and make sure there's stabilized VIT C and Omega Fatty Acids..soak in food for 5-10 minutes prior to feeding your fish.
If you only have LR in your tank, I would rec. taking it out of the tank(depending on how much you have) and then doing the hypo.. If you can't take out the LR or have inverts, your last bet is a QT. Good luck and if you have reccurrent bouts of ick infections, consider doing the hypo in your tank. Sometimes this parasite can live past 4 weeks(not by much but it happens) especially if you have LR in your tank.