Hi there all and I appreciate any help on this one. I've been successfully growing for awhile and the one area that I can't seem to get down the cloning. I finally thought I did though and now I have a new development. Where the leaves are from the center they start to bronze, a light browning starts to go all over the new leaves and eventually dies. This usually starts about 4 to 6 days in. I can't figure out why it's doing this. I've cleaned the trays with bleach and soapy water, switched mediums from Peat Pellets to Rockwool cubes, never resued and sit them in a nice dome. I can't figure this out, any help???