Welcome to AA! Those white spots on your tang are most likely ich, you may want to romove the fish from the main display and stick it in a quarantine tank (QT) and do hyposalinity, just do a search in the forums or google it to find out what hypo is and how to do it. Stay away from copper based meds as they usually cause more problems later on if you want coral or have inverts, but if you must use them, use them in a QT. Tangs are considered ich magnets by the way. The color fading on the fin of your bicolor angel sounds like the start of fin rot too me, but I could be wrong. Usually caused by bad water quality, a few simple partial water changes (PWC
) will help clear that up.