>> Sharp draining potting mixes which have high perlite content don't suck up water or moisture as well. Ditto larger pots.
I love the looks of that "humidity grid", and if they were 6-10 times cheaper I would say "problem solved". I think that MY problem is that I'm too cheap to ever be satisfied until every material comes from Goodwill or a dumpster.
I guess also, I don't travel much, and don't have any real, practical need for a reservoir. I need to discipline myself to NOT wtaer twice a day. Building a setup that meant I didn;t need to water for 4-8 days would actually frustrate the heck out of me and drive me crazy!
On the other hand, I am thinking about growing tomatoes and peas, maybe beans, in 3-5 gallon pots. If those are well aerated, they probably will not retain a whole day of water for big, fast-growing vegetables.
Hence I've been thinking "Earth Pots" ... like a water-and-air reservoir in the bottom of each bucket.
The container mix I'm thinking of would be gritty or chunky, in order to stay very well aerated. If that had insufficient WICKING as well as insufficient water retention, I might build lay some wicks between the bucket and the soilless mix. But I don't want them to rot. So I'll be experimenting with materials like nylon (polyamide) and synthetic felt, fleece or thick yarn (Polyester? Microfiber? Polypropylene? Acrylic?) It should be an "open" weave. Worsted?
i think synthetic chamois is 100% rayon.
Three issues are how FAST it will wick, for HIGH it will lift water, and how cheap it is.
I think the default would be "anything cotton" from butcher's twine to flannel, rolled up Tee shirts or terrycloth towels. And throw them away after a few months.