I came home the other day from school to find a lot of humidity and white tips forming on the bottom leaves of my clone. Im not really sure what this indicates.

I have my clone in a rockwool cube with rooting solution, inside of a large glass vase covered with a plastic bag. I have been letting the bag off to let some of the humidity out, but to my understanding it also requires some humidity... maybe thats it?

might be the rooting solution too, is there such a thing as too much rooting solution?