Guys tonite I am treating my system. I plan on treating before I go to work. By the time I get off 10-12 hours would have passed. My question is when I do my water change and I put fresh carbon back into the reactor, when do I add my crabs back to the tank? Also if I treat for a 2nd time since my carbon will somewhat still be freah from a week ago, do I put new carbon after the 2nd treatment? Thanks