These are arguably the best sub-irrigation demonstration planters of the many tested in the Greenscaper Consumer Lab. You can easily observe capillary action as it happens. In addition, you’ll be doing a good recycling deed. The other good deed you’ll be doing is on behalf of your plants. Hopefully after using these you’ll be in rehab from the misguided dogma of poke, pour, and pray houseplant care. It is the worst way to water indoor container plants. Read more here.