PraziPro?

I have no information for you on prazipro killing bristleworms. My gut feeling is actually telling me that it wouldn't kill the bristleworm. One easy way to find out is to pull a bristleworm from your tank and put it in a cup of tank water with a drop of praziquantel ( prazipro ). I use praziquantel mostly to treat internal parasites, and have had great success with it. I've personally never had a flatworm problem, so I've never used it to treat flatworms directly.

I would recommend Flatworm Exit as many have used it to great success.
 
Flatworms in and of themselves release a lot of "toxic" waste when they are killed in any large amount. So regardless of the medication you choose, and it's effect on bristle worms, you'll want to watch the contaminate levels in the tank very carefully.

My recommendation would be to manually remove as many of the flatworms and bristle worms as possible, then dose the tank to eradicate them. To remove the flatworms, the freshwater dip does wonders. Bristle Worms react very poorly to cold water. One of the best ways to get them out of the rocks is to remove all of the corals from the rock ( as to not shock them in the cold water ) and let the rocks sit in cold water ( 40-50 degrees ) for several minutes. You will see the bristle worms float to the top, and you can net them out and return the rock to the warm tank water. After manually removing as many of the pests as possible, dose the tank.

After you have given the preferred dosing method enough time to take effect, make sure you do frequent small water changes and monitor the nitrate cycle closely. Run carbon in the tank after all flatworms are dead, and make sure your skimmer is running at optimal levels. This should take care of the "toxins" released by anything that dies from the treatment. Always make sure your water is well oxygenated while treating for anything. The easiest way to increase oxygen in the aquarium is simply to remove the collection cup from the skimmer! Let those bubbles run free!

Edited by Pete Moss - January 30 2013 at 12:07pm

I used it and have bristleworms and it didnt kill them. Granted my worms stay in the sand. It will drive your skimmer nuts for 2 weeks or so even after a large water change, it will also drop your PH, if you can take the skimmer cup off and keep your skimmer running and just overflowing into the sump for airation and to keep the PH up. I also did not use it for flatworms, I used it for my fish.

I would be more than happy to help you filter out the flatworms. I can come over with a couple extra lights which we can clip on the rim of the tank after we've removed the canopy. Using airline tubing that filters through a filter bag, you can get those suckers out easily.

To add oxygen to the tank and keep your skimmer running, just put an airstone powered by an air pump in the front corner where the bubbles will hopefully not get trapped under rocks and corals.

And you can always try a Melanurus Wrasse ( halichoeres melanurus ). More often than not they'll munch on flatworms. It would control the population, but probably not eradicate it.

Edited by Pete Moss - January 30 2013 at 12:22pm

I think I will try and step up my manual removing process before i resort to any dosing.  All of my rock is superglued together, so its fairly difficult to remove anything (only way I could get the aquascape I was shooting for).

No problem man! It's not that big of a deal if you do need help, I enjoy getting my hands wet from time to time :P

And I'm glad he thought of your HOB overflowing, because I didn't and he's 100% correct!

And if you haven't purchased the meds yet, I'm 99.9% certain I have some prazi kicking around.

Stringy white discharge out of the the fish's rectum ( yeah his butt ) are a strong indicator of internal parasites, which is exactly what praziquantel was designed to kill in the first place.