Now perhaps this belongs more in the Vertical group but I know it is a topic of interest for many and people don't always notice the discussions in the groups they are not members of.
Anyway, here is a blog post with video of how I have water going into the tops of my Zipgrow towers. First part of the video shows something new I've been doing on the front porch towers that seems to be working very well. And then there is some footage of how I was doing them all before and how a bunch of the towers are still running.
Now this could be a good place for all the people dealing with water flowing into towers of all kinds or even NFT to chime in with what has worked for them.