Flatworm Stop...in tank, reef safe and supposably a great prophylactique treatment for acropora flatworms:
http://www.korallen-zucht.de/fr/shop...worm-stop.html
I have not tried it but heard good review about it. It's just that it must be used for a few months to fully work, but I might use it as a preventive because it is said to enhance the color and health of SPS even if there are no flatworms.
Raging Reef in MOntreal have just got it in, so I am guessing other stores will soon get it as well.