I know someone who has used clones which where started in jiffys and then placed them in vertical rockwool slabs from Grodan which are called v-slabs. His system is a vertyical grow like " ecosystem ". He noticed that if his roots where long enough and sticking out of the jiffy that he would have a higher rate of success ! But if the clone was rooted but the roots where not sticking out soo much that he would loose a high percentage of them. His conclusion what that jiffys hold a LOT more water than rockwool and that his roots were drowning in the jiffy. You see, rockwool needs to be water a lot more ofter that jiffy, and if your roots are not long enough to go and dig into the rockwool , they will drown in the jiffy !
What do u guy think ???