I'm gonna say try weaker light, and then tweak your solution. That's a bubble or aero cloner, right?
You'll want to sterilize it between uses and then run it with plain water adjusted to pH 6.0 for a couple hours, then change the water to FRESH 6.0 water, before adding plants. I don't think you should put too much other stuff in there.
When you say your water is over 7, do you check the water in the cloner too?
REmoving the dome slowly is important. And misting with neem or wilt pruf makes the transition less stressful. Use these VERY lightly; they can cause problems if overapplied.