80% dry is a good time to water.
What is your temperature? There's a sweet spot between too cold to grow and so warm that they rot. Try for 78'F, and start taking the dome off for half an hour a couple times a day to get fresh air in there. Lose the dome entirely as soon as the little plants can take it, because you want to avoid rot.
stinkyattic Reviewed by stinkyattic on . Where's my roots???? Hey all! After taking a nice 10 year hiatus from growing, I am realizing that I have forgotten way more that I realized (wonder how that happened?). Long story, short. I have planted seeds into rockwool cubes exactly 16 days ago. I have nice little sprouts, but there isn't any sign of roots starting to protrude from the rockwool. The cubes have been kept moist, but not wet with 1/3 strength solution and are in a dome to keep the humidity up. The spouts look great, but no roots. Rating: 5