I recently got some fresh water shrimp and have discovered they have come with hitch hikers in the form of leaches. The shrimp are small barely 2cm and the leaches or only a few mm. So I am wondering can I give the shrimp a salt bath to try and remove the leaches? And if so how much salt should i put in their water ( I have them in a container of approx 500ml) and how long are the leaches likely to take to drop off?