Sorry, new to forum and posted message but it wasn't clear what I was posting to. I think I have it now.
Holographic, what I meant was if you had any pictures of what your bottom-watering tray, your "gravel" tray setup looked like?
I know that I've had trays have a small amount of water in the "cache" tray below and I've raised the top, growing tray above the bottom one by a good almost 2" but still problems (I use large rings cut out of water bottles to sit the top tray on which lifts it out of the water).
But I _still_ get mold. I've tried everything in last 10 years and sort of things are okay now but not without a lot of effort to stave off the mold issue. Yours sounds a lot easier and sounds like it would avoid the problem altogether. But no-one else on the net so far has talked about a wicking approach and there are no YouTube videos that I can find. Again, just because I've already had trouble with drainoff that stays in trays, though water is clear, and still having mold. So wondering if we can get more details. Pix would be great, too.