I'm still trying to dechipher the mystery of some of my fish dieing. I had a large chucnk of driftwood in my tank. It had soaked for nearly a month prior to going in the tank and 95% of the tanins were out of it. Is there anything else the driftwood could leach that could cause fish death. I'm basically grasping at straws here trying to figure out why I'm slowly losing tetra's and other small fish.