Originally Posted by lion_crazz
RxP usually does not work very well. Also, it cannot be used with shrimp, lionfish, scorpionfish, and a few other things.
If it killed shrimp or crabs my fire shrimp and hermits would have been dead along time ago (and wouldn't be labeled reef safe). So far it has been completely reef safe (it does say not to use or scorpion and lionfish on the label but nothing about not using with shrimp). It worked okay for me. My tang developed ich I used it as directed and it subsided but caught it again a week later. I did the treatment again being less conservative with the dose and it cleared and hasn't come back. its probably going on two months now. I have soft and LPS corals, fire shrimp, hermits and snails. even the little hitchhiker pods and worms were uneffected. the only side effect it ever had was mild and brief sliming from some LPS corals and mushrooms and micro bubbles in the tank for a few hours after treatment. when I added my clown I did three profilactic treatments as directed on the label (with no quarantine) and still no ich. dont get any in your mouth its irritating (its a pepper treatment).
If it doesn't work it will probably buy the fish enough time and relief for you to set up a quaratine tank and more potent treatments