How are you cloning? Sorry I may have missed that? I tried the whole rapid rooters in a humidity dome like I would do for a setup that didn't require actual "rapid" rooting like in an aero cloner. So far what's working best for me is a wick cloner under LED.
Couple questions. How high are you keeping the LED up, and what are your temps in the space? You might be able to increase your growth rates given those two variable as well.
Cloning attempts:
1) Topped the biggest three plants, put the clones in cardboard paper pots. Used the 75%FFOF/25%perlite mix. Had to cover with a wet paper towel, otherwise they would wilt within 2-3 hours of being uncovered. Two of the three have survived, one croaked. All three had mold on the soil and interior sides of the cardboard pots at some point. I could sometimes keep them uncovered if I sprayed a mist on them every hour or so, but if I forgot then they'd wilt. I figured that was too stressful, so I continued to cover with a wet paper towel. Dipped in powdered "growth hormone".
2) Next set of clones were various bits from the three biggest plants, and placed in the Burpee seed tray. The bottom of the seed tray sits on top of a cotton wick mat, and the edges of the wick mat dip into a bottom tray full of water. Only one of seven clones survived, the others molded. It worked really well for the one that survived though. Also all were dipped in growth hormone.
3) The final set of clones were taken a day or two after starting the 12/12 cycle. I put all of those in quart-size glass jars, and put the jars in a window that faces the ocean (for access to the warm setting sun on clear days). Dipped in growth hormone. No roots yet, darn it, but all of these clones have healthy turgid leafs and firm stalks. My only fuckup appears to be not cutting just below a node and not changing the water each and every day. Oh yeah, and I put a little (just a little!) brown sugar in their water, just to see if it would help things along... got slimy mold within 24 hours. Gave all the clones a good cleaning after that, and have been changing the water daily for the last 4 days.
I had the LEDs at about 14 to 16 inches for veg, and moved them up to about 20 inches for flower. The move on flower seems to have added quite a bit of stretch, but that's ok (I think, and if I'm wrong, please say something!)
I keep the temps around 70 to 75 during light, have had things go to 84 once but that's unusual. At night for the past 30 days or so, it's been 55 to 60, sometimes a little warmer but not too much.