make sure you are not giving the clones too much light.....gentle light for the first couple of weeks til rooted (leave it alone and don't check for roots for at least 10 days...2-3 weeks is better). when i first took clones my 400w metal halide hid was killing them 2-3 ft away. solution.....put a sheet of newspaper over the humidity dome and it blocks the right amount of light so i don't have to move the reflector. ..... the more light the plant gets the more energy it puts into photosynthesis when you want energy going into rooting. you need very high humidity til clones root too....if humidity is too low your plants may droop. if you don't have a dome place your clone in a bucket or something with a little water in the bottom and put a clear plastic plant saucer or plastic wrap over the top (leave saucer slightly ajar or punch holes in plastic wrap so it can "breathe" a little.