The more I’ve thought about it, the more I realized that I should look at an alternate body for this project.
The window boxes will be better served as part of a trough/ebb and flow irrigation solution than a full-on hydroponic bed.
I was able to pick up 10 feet of vinyl downspout and a bag of 5 elbows for $30.
I’m very pleased at how much more I’m going to be able to grow, in a comparatively smaller footprint (The downspout is much narrower than the window boxes)