I have a new tower set up with new seedlings and the bottom row is wilting. I have the same seedlings in the second row, which are thriving. The tower is indoors with lights going all the way to the bottom. I've checked that the water is reaching the bottom plants. Any thoughts?
What is your water pump timer set to? You may want to reduce to 15 minutes on and 45 minute off if you are currently using 15 minutes on and 30 minutes off.
I use the short end of the water port lid to space my lights the appropriate amount from the base of the grow port lid.
You may also want to move the location of the plants and see if a hardier plant from a higher grow port wilts when moved to that area.
Experiment and see what happens.