First, we don't really recommend it in a marine tank. If you have fish only, you might be okay, depending on the species. Second, do a partial water change, and treat each day, as long as the fish have spots. If the spots have not gone away, you treat the next day. Keep treating till they are gone, basically, which can take 3-7 days.
This product will harm beneficial bacteria, so be prepared to boost your biological filter with Instant Ocean Bio Spira, after treatment.
Date published: 2016-10-11