clones roots appear to be growing above the rockwool cube?

[invision]

I've seen it before. You can cover them if you want. It won't make a difference. The roots above the medium will develop like a stem-like skin, in the same way that tree roots do when they protrude above the soil.

i never did think of that, i have a few plants where a couple root vines come above ground and they are thick and strong like the stems, glad to know i dont have to be too paranoid about it i just cover it back up.