A tank does solve the uneven-watering problem, and it introduces three others. What wicking actually is, where it works, and the weight nobody mentions.
A tray that overflows is worse than no tray. How to size one from your own runoff, and the two floor failures that happen without a drop ever spilling.
Water in equals water out, or water held. There is no third option, and deciding which one before you build is what keeps it off your floor and your wall.
Leaving a vertical garden while on holiday? Why the top dries and the bottom drowns, which method suits which trip length, and when you need a person.