My grow is off to a late start. The tap roots have emerged and are now visible after day 22. The water has been changed twice and I have added water to try to make sure the roots are fully submerged. Also should the fans have kicked on yet? The leafs are no longer yellow but it is way behind where it should be.
Your roots are not supposed to be fully submerged, the water should just bubble up and hit them.
Your grobo has sensors for the water levels that change according to the stage your plant is in, so be careful adding water to reach high levels because it is possible to drown/rot/ your plant. Try and let your grobo do what its made to do, try not to worry so much.
Your fans should be on now, bottom one for sure, top may I take another day or two.