I used flatworm exit and it is a pig dewormer. BE CAREFUL please, as the flatworm is very toxic. When the flatworm dies it excretes this toxin into the water. When I first did this I killed many fish. What you need to do is figure for every one you see, there are 10 hidden. I find they usually live on rock. I bucketed water mixed that was good clean r/o water with the temp the same as the tank, and mixed with salt - heated to 78. I dosed each bucket, and moved each of all my rocks to these holding facilities for the half hour treatment. Then I treated the tank almost empty, just fish. The toxins were less in the tank. Ran activated carbon HEAVY with 3 canisters. After the rock and corals were treated I reintroduced them to the tank. Make sure you "swish" the rocks around in the buckets so the flatworm exit gets in the dead spot areas where water flow is still. Then most of your toxins are in the bucket and down the drain when you empty the bucket water. Do not put the bucket water in the tank. I did this with 300 Gallons. Believe me, they got so bad I couldn't sleep. They were everywhere. they loved my halides and became worse a coral threat than the final straw - the stealizing of the tank. Nobody wants to pull their corals. The first time when I did treat the tank, the water turned orange, and I was just prepared with carbon, and a 25% water change. I lost a yellow tang, hypo tang, a pygme angel, and a lawnmower blenny. The second time 6 months later with the bucket plan, all my livestock lived with the exception of 1 small colt coral. good luck and please don't take chances with the orangish flatworms. they look like rust right?