i have 4 fish in my 45 gallon tank and at one point they all had ich, not badly tho flashing here and their, ive been treating their food with vitamin C and garlic xtreme for awhile now and im noticing the flashing has greatly reduced does this mean the ich is gone? or when i go to put another fish in because i do want to add atleast one more will that new fish just contract the ich again like the others basically re introducing it to my tank