Show us a picture , i'll be happy to help. Also FF Grow big has nitrogen in it so it most likely wouldn't be a lack of nitrogen as I stated earlier unless your using a small amount. I just read you use a full dose. What is the PH of your water ? If its too low or too high it could be messing with your plants.
Do you have roots on your clones yet? Yellowing with no roots? Keep the temp around 80* and make sure its humid in there. I've always used "domes" not an aerocloner.
When using a "dome" I keep a heat pad underneath it for ample heat and also fill the bottom of the tray with roughly a quarter cup of water. The heat pad heats the water keeping the dome hot also I spray the sides of the dome to keep up humidity.
Taking a wild guess on your aero cloner I would say the ph may be off or the water in the cloner might be getting to cold. The temp. in the room your cloning in could be too cold. Temperature in your cloning area is very crucial !!! post some pics ! on a new thread and message me. Also are you using just water to feed your clones with ? If so , add something like liquid karma or Clonex "solution" not the gel to your water. You will have much better results using one of these two !!