I added the cories for only a day and a half. To say the least they didn't make a dent on the worms. Everything is pretty much the same, aside from more worms since they just keep reproducing and reproducing. As soon as possible I'm going to remove all the shrimp and brig snails and then break down the tank to get rid of ramshorn snails, pond snails, and the substrate that is housing all the worms. I've considered putting the substrate in a styrofoam cooler and keep the worms to feed to my fish--after freezing them this time. No more live worms are going into my tanks! LoL