i don't know what you have in your tank or what you will have in the future. i know that maracyn-two will help your fish with secondary infections that they are having at this time. Mardel is saying that Mardel copper safe is o.k. to use with their antibiotics at the same time. but copper itself is bad for inverts if you have any. because many inverts are made of the same material as ick. Quinsulex is great for protozoan of any kind, but will kill invertebrates too, but easy to get it out of the reef system, unlike copper. i used Quinsulex for ick and it did great job too. But I don't know if you can mix it with Maracyn-two. These two meds are my favorite for two different things(Maracyn-two and Quinsulex) tell me more and i can help you make your choice for the moment. You meybe will have to go to the fish store to get it.