[Pavel Chaloupka]

Well I was not speaking negatively about all chemicals and of course using for example copper sulfate and dosing it in to the tank is very dangerous. The method with soft piece of copper metal was suggested by RNDr. Stanislav Frank in his books where he describes this way as quite safe as you dont get high concetration quickly and if you watch it closely you can use it quite safely as the concentration that becomes highly toxic for hydra are usually not dangerous for the fish yet. I think we can agree that most of the substances we use to get rid of parasites or pests are usually just less harmful for fish than for these organisms. If flubenol is safe for use with Paros, its great. I have used above stated method many times even with some quite sensitive SA imports. But you are right Peter, there may be methods that are safer for use for people who are newer to the hobby.