its not the only way to treat them. I've had zoopox infect a few of my zoos and I only lost two out of 6 colonies. Almost lost 2 more but saved 1-2 polyps.Zoapox usually forms on the base or stalk of the zoa, not the head. It'll look like whiteheads just under the flesh. Only way to treat them, and I've only had sucess 50% of the time, is to do a Furan 2 dip. One packet in about a cup of water, mix well, set zoas in dip for about 15 mins, rinse in fresh RO, and put back into your system. Do 3 or 4 consecutive days of dip and let it rest for a week. Some heads may turn brown eventually and look ill. The best I can tell you is to carefully disect the head off of the matting or base portion with an xacto knife.