I used to use water cloning (when I grew) so I never had clones in a dome more than a day or two. This eliminates most problems associated with humidity induced diseases.

bottled water. Narrow neck dark container (I use beer bottles), keep temps at around 75-80 degrees, a steady but not powerful light about 6 ft away (60watt). Top up water every day, wait for up to two weeks for roots. Transfer to dome for couple days so they can get more intense light for growing roots without wilting/drying. Viola! New clone.