well,,,,
7 years ago, my multi tank frag system got a nasty case of red planaria. They absolutely prospered and grew into a bright orange matt a quarter inch thick covering the entire plenum sand beds, rock and frag rock. and were climbing all over the glass and corals.
There was no patented formula for ridding them then. Pre-EXIT era, so to say. I experimented with things like melafix, which in pretty good doses, seemed to kill about 75% of them. Making the water bright orange, smellining like iodine and driving the protein skimmer absolutely wild!! Like adding laundry detergent to an automatic dish washer. If you have ever done that. but that didn't quite do the trick.
so i tried what a local store does to rid their tanks of red planaria , when they get them. They usually tap water dip the macro that customers bring in for sale or trade, to rid any flat worms and such. but forgot one time. They got infested, and I bought a frag from their tank system. VOILA! Red Planaira everywhere! enough said.
So they just fresh water flushed their whole wall tank system, and sump to rid them. so i figured , so would I.
I first syphoned out as many as i could. One idea i have seen on RC, to syphon flat worms to a filter sock in the sump works very well to capture most of them. then bleach the sock. then i removed each coral, frag and rock, one at a time, and blew the loose flat worms off them in a bucket of tank water with a power head. then place them in a tray, tub or tank of clean salt water. then I put a bunch of power heads in the vacant tanks to swirl the water around in a circle while filtering any loosened flat worms with the over flow filters and an HOT micron filter. stiring up the sand bed while i was at it to get the dirt out too.
Then i syphoned all the water out of the tanks as deep into the plenum sand beds as i could. refilled the tanks with tap water from a garden hose. and ran the sump pumps to circulate for 5 to 10 minutes. Drained and refilled with new salt water. then i replaced all the corals and rock ONLY AFTER giving each one a 20-30 second swirling dip in RO water to kill any remaning flat worms in their base rock. And that was it.
I never saw them again in that system.
But i got them again recently from some frag. so right now, im doing an EXIT treatment. and if that fails. Thanks to a friend who directed me to this thread, I do think i will experiment with the Lamanisole treatment, as there is a Tractor supply just down the road. sounds like a good idea.
I'm in the process of tearing this sytem down anyway to replace with a larger tank. I want to salvage as much as i can from the tanks, and rid them of pests and algaes. a whole new curing project.
One of these methods should do the trick for me.
Thanks to all for all the good info!