hey:
this is a never ending questions. I think between all of us here, if someone stumbled upon a reefsafe med which actually worked greater than 50% of the time, we would be harping its praises. Infact there isn't one.
As Terry mentioned the only two time tested, tried and true, guarenteed to work methods are copper-based meds (cupramine is the best), and hyposalinity. Neither of which are reefsafe.
Curently garlic enriched foods might be a close third, but it seems to work only in light infections and on when given early on
Good luck
frank