My personal approach is seachems paraguard as instructed or cupramine at .2ppm. I've QT'ed a dozen mandarins in the past year like this with no deaths. To be fair, I make sure they're eating live brine at the store and have been lucky with a reputable company mail order for the red finned greens). Many of them were without a doubt carrying cryptocaryon, however, (and a few had brooklynella) based on microscopic confirmation. You can also do "musical tanks" and switch them to a new tank every 2 days just twice to effectively beat the life cycle, the cycsts on teh fish fall to the bottom to grow and while they're "sleeping" you switch the fish out and clean the tank.
Also, maybe use the opportunity of no heckler fish to wean your mandarin. I've gotten more than half of the mandarins I've QTed (for myself and others) on ocean nutrition formula 1 small pellets using the strategy outlined in last november's "Coral" magazine.
Also, maybe use the opportunity of no heckler fish to wean your mandarin. I've gotten more than half of the mandarins I've QTed (for myself and others) on ocean nutrition formula 1 small pellets using the strategy outlined in last november's "Coral" magazine.