Need advice on my clones

My 20 clones are at day 15 now and have not popped roots. They all look perky with some of the lower fan leaves starting to yellow a little, which is apparently considered normal.

Growing impatient, I gently pulled apart the rockwool on two of them to check if they are even growing at all. See pics.

Some info on my cloning process:

Soaked 1.5 inch rockwool cubes in distilled water at ph 5.6 for a few hours.
Shook water out of the rockwool so it was not dripping wet.
Cut clones at 45 degree angle across a node, scraped bottom 0.5 inch, dipped in Clonex, inserted into rockwool.
Placed in dome under one 14w T5 @ 6500k and temperatures kept at 75 degrees F. Humidity 100%.
Remove dome every 4-6 hours to allow air.
Day 10, I felt the rockwool cubes could use some more water, so I top watered them lightly with a weak Maxibloom solution at 0.5 ec.

Seems they've popped roots, but things are progressing super slow. In the pictures you can see some white stuff growing in addition to the actual roots. I can't tell if this is normal.

Am I just being impatient? Give them more time? Dump them?

EDIT: I forgot to mention these are Great White Shark, an Indica dominant strain. Don't know if that makes a difference.

They are rooting. Leave them be. I did the same thing you described at about 13 days. Looked very similar to what you got going on. 8 days later I got new growth and looking pretty good.

Ok thanks. Good to know. Will give them some more time. Was really worried I'd have to start over.

I been playing with dome lid vs no dome lid. with no dome lid my clones first wilt then stand the next day, and root in about 4 days but with a dome they never wilt and take 7 days or so to show roots. RH, feeding through the leaves, dunno. I keep the dome on , hate to see a wilt.

The other day I left the dome lid off for about 6 hours and they still looked fine. No wilting. I'm still using the dome lid however more so to keep the temperature for the clones a little more stable. The room they are in fluctuates between 70 and 80 degrees, but the temps under the dome deviate less from 75.

Rock wool sucks use jiffy pellets use heat mat don't top water them spray dome lid twice a day keep humidity high after 3 days take lid off few hours a day after a week remove lid

Castel said:

The other day I left the dome lid off for about 6 hours and they still looked fine. No wilting. I'm still using the dome lid however more so to keep the temperature for the clones a little more stable. The room they are in fluctuates between 70 and 80 degrees, but the temps under the dome deviate less from 75.

Click to expand...

confirmed-

youre trading a constant temperature(not necessary) for retarded root development. could choose another option.

I think you're right about rock wool. Next batch I'll use jiffy pellets. I'll remove the dome now, but how should I then water the rock wool if I find it getting too dry, if not from the top? The room they are at the moment averages around 60-70% RH, but I'm pretty sure they will dry out pretty quick none-the-less.