If you read up a bit on the lifecycle of ick, the solution becomes (at least to me) failry clear
. lifecycle in a nutshell: ick floats around in the water column, attaches to FISH and parasitizes it. It reproduces and it's spore-like offspring fall onto the substrate and grow into more ick. yay fun, fun.
So how do we get rid of these ****ers? Well what I would do is give all the fishies a short freshwater dip (5-10 minutes should do it). this will basically explode the ick off the fish due to their intolerance of hyposalinity (lack of saltiness). After that I would throw the fish into QT for a month, add meds if you want.
Why the month long QT for all the fish? Because it takes away the hosts from the ick lifecycle and they die without a proper host (fish). From what I understand ick cannot infect corals or inverts so those can stay in the display tank. PLus I dont think inverts and corals deal nearly as well with freshwater as the fish. If something IS infecting your inverts/corals, it probably isnt ick.
Keep in mind though that before you do any meds or drastic measures, make sure that your diagnostic is correct. Also not all disease-kill procedures are suitable for your particular tank. You have to think before you act.