I wouldn’t recommend indoor growing for plants needing pollination. Even the air pollinated ones will pollinate poorly in the absence of winds and growing insects in a drawing room is impractical (though my vote would be stingless bees - you’ll also get medicinal honey).
But mostly you’d have to rely on manual pollination.
Also, I’m not sure the towers will support anything needing serious pollination (most plants will bolt or put on a growth spurt before flowering). Even something as simple as tomato plants will quickly get too big for these. Not to mention they are technically growing diagonally and may not support the weight of fruit as happily. Greens, as @jtd is doing feels like the most productive way to go for the least effort.
That said, returned here after a long time and really thrilled to see this project going strong.
@jtd, I’m surprised that the pH needs such extreme adjusting. I can’t recall this from hydroponics posts and such I’ve explored in the past - if I recall right, they balance the nutrients and for the most part, that’s enough - but I also think they discard the nutrients after some time, so… you mentioned the pH rises in sunlight, implying some relationship with photosynthesis. Have you tried to see if it returns to normal in the night (or even partially)? Obviously stopping photosynthesis alone wouldn’t do it, but whether there are processes that happen in the night with the opposite effect.
Asking, because I was wondering how they manage in the wild without intervention. While an established ecosystem will be much harder to disrupt than plain nutrients in water, the sheer amount of foliage in the wild would at least result in some instances of plants simply running out of survivable pH. This doesn’t appear to happen, so I’m wondering if the plant’s pH fluctuations might be less than they sound. Or if combinations of plants result in an overall mitigation.
I have an idea for your next product - a “growing panel” of smaller pipes fitted on a frame. Holes in only one direction, less root space, can grow with directional light (like standing against a wall…) for those without lots of space, but can stand or nail something to a wall…
Ignore if I’m saying irrelevant things. I haven’t been here in a while.