Just so you all know and realize, that even a sucessful tank is not without the same problems other's encounter.
A few months ago I found out that I had the dreaded AEFW. !! Inspite of being careful with dips and inspection, I guess some of the eggs must have sneaked in. It took me a while to realize that the reason for some color loss and blah look on a couple of corals was due to AEFW.
Once I learned to recognize the signs for AEFW on a coral, it quickly explained some of the problems I was attributing to lower alkalinity.
There was no way I was going to tear down the tank, frag and dip and destroy the corals like I have seen a lot of people do. After consulting with several of my friends who I have been in the hobby for a long time, I decieded that the best strategy is to live with them, but stay ahead of them by making yourself thier main predator. These friends of mine have very nice tanks and you cannot tell that they have flatworms.
The strategy was to blast the corals regularly with a water jet form either a turkey baster or a small powerhead. When the flatworms get blown off they get eaten by the fish. The larger ones are really easy to blow off the coral. They tend to hide towads the base and lower branches. The 2nd mode of attack was to seek out any potential egg masses and get them out of the tank, especially since the smaller ones are harder to blow off the corals.
Here is a picture of the mother lode of all AEFW eggs.
Now my maintenance tasks have one more task added to it. Every 3-5 days I go in with a turkey baster and knock off some flatworms. In the begining I was doing this daily. Now I only get a couple of few comming off the corals every 3-5 days. This keeps thier numbers in control and the damage is minimal. It sucks having to add an extra chore, but doing this has made me more in tune with the coral's health and better at spotting damage before it get out of control. Also, having larger coral helps.
On the brght side, it have opened up a lot more people that I can now trade with - I was avoiding them since I knew they had flatworms.
My advice.. if you are really paranoid you should set yourself a quarantine tank and be absolutely strict about what goes into your tank. If you do get them, and can remove your corals easily, then put them in quarantine. Often times the treatment will kill the corals faster than the flatworms will. If you do get them in an established tank, then learn to live with them. There are a lot of successful reefers around the world that have beautiful tanks and are living with the flatworms.
sanjay.