Looks good. What strain are you growing that the leafs turn black?
Also for cloning I found out doing a Aero Cloning method is very lazy way of doing it.
1 - Take cuttings long enough.
2 - Dip them in rooting agent and put them into the system.
3 - Turn system on and check up on them once a day or every 2 days if you want. (I've gone with out checking up on my clones for 7 days)
4 - When you see root bumps on the bottom part of the cuttings, drain and clean the cloer the plugs and rinse the clones nicely then put a small almot of Super B+ in it.
Wait about 3 days to 7 days and they will have a nice root mass. Plant them in soil, put them in their how hydro system or keep them in the aero cloner give them a shot of Prop-O-Gator and their root mass will get nice size. Imo any other method of cloning besides Aero Cloning is alot of effort and takes longer to root.