Welcome!Ok so I’m new to saltwater aquariums n I just ran into a major ich problem. Do I need to treat the fish in the infected tank first and then move them to quarantine ? Or move them and treat them in quarantine? Also do I need to remove all the sand from the currant tank already set up ?
Glad you joined. Posts #4 and #6 if not also others have some good summary info and there is also good reference for future question postings in Forum(s). Vetteguy really knows his stuff, so take his recommendation to post photo seriously to ensure it is really marine Ich.
Healthy well established fish usually pull thru Ich (fingers crossed), but so many things can be factors. Wishing you much success!