Reef Archives
My Problem with Flatworms
I started having a flatworm problem in March of 2001. Within about 4 - 6 weeks they went from less then 10 to the numbers you see in these pictures (Click to Enlarge). Flatworms are toxic and have no known predators available for use in a reef tank. Some people say mandarins will eat them, and chromis, but I've never seen anything touch them. In fact I've watched my mandarin take a bite off the bottom and spit the flatworms out.

You can try Oomed, but that just wipes out your other detrivores and potentially will crash the tank. I have been told that eventually the population will just crash, but it's been 6 months and I am still waiting. I've tried to cause a population crash. The first attempt came when I ran my alk up to almost 13 dkh, ph at 8.4 - 8.5 and temperature at 85 - 86 for almost 10 days. Nothing.

The population seems to gather in all types of currents, but generally seems to avoid direct lighting, staying on the bottom sides of rocks and other objects in the tank. The first picture on this page shows the flatworms completely encrusting some caulerpa in the front of the tank. So far they seem to avoid my corals.

The picture on the right shows a cleaner shrimp just above the sandbed that is covered with flatworms. They really seem to go after the diatom films that gather in different parts of the sandbed, but are certainly also present in huge numbers on the live rock as well. I've tried everything I can think of, so any suggestions are certainly appreciated.