This might be kinda random, but thought I'd share, cuz I just read it and I'm like OHHHH!!!
So I've had some frustration when cloning as my cuttings have a hard time rooting. I mean, I'm not saying I've never had my cuttings root. I'd say 75% of the time they do, which although I'd like to increase this number, that's not my main problem. My main problem is typically my cuttings leaves begin to yellow and wilt a bit. I have tried a lot of things but like with everything it is often the smallest (and hopefully the simplest) things we miss. With that, I share with you this piece of golden info (to me anyways, many of you probably already know). This is an excerpt from Marijuana Garden Saver (avail. on amazon and likely local book stores).
"Yellowing leaves on cuttings
When unrooted clones start to yellow
it means they are either not touching the
rooting medium good enough, to much co2. The vast majority of the time, an
unrooted cutting will begin to yellow some of its leaves, starting with its largest
oldest leaves, because it is
too close to the lights and it needs to be moved
farther away. Some yellowing is normal just as the cutting begins rooting and can
be a sign of the cutting using its oldest leaves as a food source while it is forming
new roots. Plain tap water that is ph adjusted is just fine until the clones have
rooted. Giving any ferts will kill them until they have been rooted."
Hope this helps a few peeps with their cloning endeavors