I just completed my vodka dosing and all my levels are at zero. My yellow tang just started to rub "flashing" against my live rock. I am aware that this could be a sign for ich but I haven't noticed any salt crystals on his body, fins, or gills. I have a cleaner shrimp so if it is ich can he remove the parasites or does he have to be quarantined? I noticed he has been trying to let the cleaner shrimp on his body more frequently.