Does anyone out there really know what to do about flatworms. I have an SPS tank, everything is in balance, and all the perimeters are good. I thought that everything was in balance, but noticed that I have a nice infestation of brownish-red flatworms. I tried siphoning them with a small tube. I got a lot of them, but a day later they are all back. I have been reading on line and have heard everything from blue velvet nudi branch (which seem impossible to find), 6 line wrasse, as well as other types of wrasses. I have a psychodelic mandarin, but he doesn't seem interested in them. I really don't want to go chemical, as in FWE. I have also read that eventually they will die off. Any ideas, anyone? Please help!