I have added them at both times I have not really seen a major difference. As long as they have something to chew on in the fall when you add them before winter hits I think they will be fine. The one thing about adding them in the fall is you may start to see progress from them come spring time. If you add the in the spring you won't see any changes more than likely till the next season. It takes about a year before you really start to see what they can do.

RC

OH and I would get 10 to 12 inches if you can that helps speed things along a little. Plus they won't get ate if you have any predator fish. I put a few 6 inchers in my pond and I don't think they made it?

The only difference between a rut and a Grave is the depth. So get up get out of that rut and get moving!! Time to work!!