Thanks for all your help with this. I dont think im quite out the woods yet as the corys are far from normal behaviour. But I guess I will find out over the next couple of days. When do you think I should try a shrimp back in there? The plants are going crazy atm. No fets and NO co2. hairgrass shoots everywhere. Reason I was thinking of the MTS is purely to turn over the top layer of substrate. But thinking about it they may become a little more of a nuisance. We will see I guess. Could keep the assassin just to control numbers a bit. All the planaria are now dead. All the hydra are dead. I am going to do a 50% water change tomorrow to remove any of the Panacur that is still floating about and dilute it down. I wonder if then i should test a shrimp?