White Planaria flatworm. These flatworms can quickly multiply in number and, as you will soon learn, can be dangerous to other members of your aquarium especially shrimp, snails and their eggs. From a veteranarian, Fenbendazole. It will eradicate a planaria infestation in just a few days. It’s like a planaria nuke! The dosage is 0.1 gram for every 10 gallons. So a 60 gallon tank would need 0.6 grams of Panacur C. A gram scale will make measuring this amount easily – Then sprinkle this powder into your tank.
Remove as many of the dead bodies as possible with a siphon while performing a water change.