those cuttings look fine to me. that white part of the stem looks like a callous, which preceeds roots. i've never used cloning gel so the size of that particular callous may be gel specific, but i think you'll find you have roots within the next week or so. honestly some strains can take up to three weeks to root.
experimentation (your gel vs. no gel) is always helpful, but i think you're on the right track. as long as your leaves stay green and soft, you'll have roots eventually. promise.
I agree with trying a batch without using the gel as a test, however after 8 days I would expect more root growth than that regardless of the gel, or even inspite of it.
RE the OP: Im presuming youre doing the usual 45 degree cut under water, scrape the bottom half inch lightly, maybe a small split up the middle from the bottom, always ensuring no air gets inside the cuts?
Using a sterile and razor sharp blade, and fresh cloning gel (having not been dipped in on prior attempts)? Have you pre soaked your rockwool in pHd water, and then expelled all excess water (you can check this against a weight that has been posted many times, give it a search)?
What light cycle are they on? What surface temp is the dome sitting on?
If you look at these things, you'll spot any human error. Otherwise just leave them be, maybe its just a very hard strain to clone and takes a long time.
RE the ezcloner: Theyre a great system, but not necessary, and it has its own inherrent problems. Rockwool and a humidity dome is basic and works very well if you do it right (which isnt complicated)
