i never used a dome with the bubbler. i just cut holes in the plastic top of the container and stuck the cuts in, no rockwool! i would just make sure the mum was watered well an hour or so before the cuts are taken. very very simple. ph about 5.5 or a little lower, water temp 76-78, air temp 79-81, agrosun full spectum flouros about 16-20inches above the cloner. if the lights are too close the cuts try to grow instead of root and end up yellowing out real fast. those are the conditions i have for cloning and i always have excellent results. another thing i have noticed is that smaller cuts with fewer/smaller leaves seem to root alot faster than the bigger ones. good luck.