new clones with brown spots

I took these clones 3 days ago. Using rockwool, been misting them a couple times a day and keeping them under a humidity dome. Today they have these brown spots on them. The babies are telling me what they need but I don't know what is. Can someone provide me some insight?

ph'ed the water and its around 7.4, could be the issue. Will re-adjust to 6 and see if they get better. The rockwool cubes were orignally soaked in ph of 6. So maybe they are going through a ph shock of some sort??

i get the same problem, but my ph was low around 4.3 got it to about 5.9 and it stopped. but i did start to foliar spray the same day i fixed the ph. so no i dont have an answer for you to what the problem is. but thats what i did and the problem topped

what type of foliar spray? thanks