Hi, prof Bachman, thanks for the comment. I mentioned that I had glued a piece of mesh wire over the overflow with silicone to hopefully prevent something creepy from entering. I pretty much am expecting a clog someday from the mix getting stuck in there, but I'd rather dump the box occasionally than to encounter a snake, eek!
I packed the corners with soil enclosed in a section of pantyhose to try and keep that part of the soil from merging into the reservoir, so maybe it will be a while before I run into clog issues.
Right now, I have eight very nice lettuces growing, seem to be doing well.
Your videos from the Heritage Cottage Urban Nano Farm are very helpful, thanks a bunch.