what about setting up a tank for all your live stock, every last fish??? Treat all fish in there for about two weeks, make sure this tank has got great filtration, heaps of hiding places and no light. With your display tank fishless the parasite will eventually die of starvation, daily vacuum this tank to remove the infant stage of the parasite, as well as treat the tank with salt (warning: the salt can have a detrimental impact on your plants), and as stated increase the temp to 30 degrees (this increases the speed of the life cycle of the parasite).
good luck if you move your fish quickly they will still be quite strong, so shouldnt have too much of a negative impact on the fish.