Wow, thanks for all of the help.
<You're very welcome!>
I'm relieved that they're not the nastiest of flatworms.
<No kidding. These are nothing compared to some of the other troublemakers.>
I'd still like to get rid of them or at least try to keep them in check so they don't kill off all of the pods.
<I can understand that - especially if your tank is relatively young and you're wanting to establish a good stock of copepods. The good news is that even with a new system, you'd need a virtual plague of these flatworms to threaten the entire stock of pods.>
I don't want to use chemicals and I assume a wrasse would eat the pods along with the flatworm, so for now I guess I'll just suck them out with a turkey baster when I see them.
<Yep, sounds good. These guys will probably just disappear on their own, but in the meantime, you can always remove those that are visible/accessible.>
I didn't realize the little spiral things were 2 different species.
<Oh yeah - there are all sorts of tube-dwelling critters that show up in tanks. Just the spirorbids alone have many genera and species, not all of which are flatly coiled. Some have the opening lifted up and away from the coiled base. Some have longitudinal ridges on the tubes while others are smooth, Some coil to the right and others to the left, but what they have in common is that they're all small, usually less than 7mm (~1/4") and are filter-feeders with a "feather duster" crown. I'd love to be able to tell you what species you have but it would take someone a whole lot better than I am! Apparently, the only way to really know for sure is to remove the animal from its tube and examine it under a compound microscope>
I had thought about scraping them off the wall so thanks for the warning about them being sharp. So far they're just in the sumo, and I'd like to keep it that way.
<Yep, the little flat spirorbids are pretty easy to scrape off. The vermetids can be a bit tougher if they're adhered to rock, but tweezers work pretty well.>
I also didn't realize how many different kinds of pods there are.
<Oh yeah, there are many. The most commonly seen are the munnids (typically < 5mm long; see photo in the previous post), gammaridean amphipods (can get up to ~1/2" but most are a lot smaller):
and the copepods - these are harpacticoids and they are very tiny. They look like small whitish specks on glass:
I'm going to have to check them out better and see if they're all the harmless type.
<Thankfully almost all are harmless/beneficial and serve as a good food source for fishes, corals, etc.. Here's a terrific article by Ron Shimek with more info:
http://www.reefkeeping.com/issues/2004-08/rs/>
Maybe the pod eating flatworms aren't a bad thing.
<Heheee! Well, the copepods are almost certainly harmless/beneficial, so no worries there.>