I've been having some cloning problem as well. I've got mothers vegging and have just recently started to clone. I'm on my 2nd batch of 4 clones and only had a 50% success rate on the first batch. They took a long time too root as well; I noticed roots around 2 1/2 weeks in. My current batch of 4 has been rooting for a week and no sign of roots yet. Today the leaves were starting to yellow. I've read a lot about cloning and I don't know what I'm doing wrong.
I get branches about 6" long, with multiple branches off it. I cut the bottom about 1/4" below a node at a 45 deg angle. I pull off the leaves at the bottom node, peeling the stem skin off from the node to the cut. I then dip this in water then into powder rooting hormone. I shake off excess and insert it into a rockwool cube that was pre-soaked in distilled water. I have wicks (for oil lamps) stuck in the cubes and in a reservoir of distilled water to keep the cubes wet. I then spray them down with water and put in a tent with 2 2' floros about 1" from the top of the tent. I keep the light on 18/6 and spray clones occasionally.
My only 2 guess are that the cubes are too wet from the wicking or that the wicked water isn't oxygenated enough since i don't have a bubbler in it.
Any thoughts on what I'm doing wrong, or what I should try on my next batch?
Also, how long should it take for roots to grow out the bottom of a small rockwool cube?