Here's a little tip I can pass on to you that may save you some effort. The bottom collection bin does not have holes - it collects the water. So what I would do is put one of my fodder bins with holes in that bottom collection bin in the morning. I would also put my seeds in that bin. Then, when I watered the tower, the seeds in the bottom bin would start soaking. That evening, about 12 hours later, I would take the fodder bin with the soaked seeds out of the bottom collection bin and put it on the rack for draining. This worked great for me because all the bins were the same size and fit into each other.
I know some people soak their seeds separately from their bins and then dump the soaked seeds into a fodder bin for the rack. But you don't have to do those extra steps if you soak your seeds in a fodder bin (inside the bottom collection bin) to start with. I hope that makes sense. This system works for me because I only soak a new bin of seeds as I take one bin off the rack to feed to my chickens.
Anyway, will be looking forward to your results, and if you start a new thread on this topic, please come back here and post a link. There are so many threads on BYC that it is easy to miss any given posting. Thank you.