The best I’ve found for eradicating planaria. Only one drop per 10 gallons for three days and no more planaria. 10% water change advised after three days.
X2 BBS Planaria killer
Planaria Killer is a special killing agent for Turbellaria and hydra. It can kill live insects and their eggs and does not hurt shrimp.
1 drop per 10 gallons of water for 3 days.
10% water change recommended after the third dose.