Freshwater dips are NOT for LR. That will kill all of the bacteria. Freshwater dips are for fish, parasites will drop of in freshwater. To remove hithhikers from LR you should use supersalinity which is placing the rock in water with a high salinity level. This will not kill the bacteria but unwanted hikers such as mantis and fire worms will leave their hiding spots in search for better water. Once again don't put your LR in freshwater!!