hi i have a 180 gallon aquarium with a 40 gallon refugeum and i just noticed some spots on my two smaller oscars 6-7 inches. my 14 incher not yet and the bala shark and convicts not yet neither the pleco. but i think it may be stress because i just recently added the 14 inch oscar and the smaller ones get pissed off. im not sure why but the 14 incher does not get mad or anything he just minds his own bussiness. well anyway i read that ich can attach a fish easier if they are stressed. i need something to cure it and it needs to be enough for the treatment for a 220 gallon aquarium. what should i buy. help pleease