Move coral and inverts into the 340g when cycled and let it go fallow for 72 days while treating the fish in the 55g with cupramine,Chloroquine phosphate, or TTM
Do not use CP with a hippo tang. The only time I would advise this is if you're dealing with a copper resistant strain of ich, even then I would try TTM first.
To be 100% sure there is no ich, they all need to wait 72 days. After you treat, you will need to sterilize the 55 or you risk having a tomont hatch.
Thankssoaking in fresh water for 5 minutes then putting into my 140 with it ich free won't do the trick huh?