1) What makes you think light is bad for roots of other plants?
2) Those pots look intriguing, but I have three concerns:
- the outer part that serves as the reservoir is apparently as tall as the inner pot that contains the medium and the plant. As such it can be overfilled, drowning the roots.
- Being totally closed, it also means you'll have to periodically remove the inner pot and flush the medium thoroughly.
- Even if you overcome-, or are willing to contend with those drawbacks, and keep the liquid level no deeper than that protruding section at the bottom of the inner pot, its small diameter means that you'll be trying to wick to the whole potful of medium through a small channel, which will be OK if you are in very high humidity, but won't work well at all under reduced-humidity conditions. (Remember that you're trying to balance the evaporation rate from the top of the pot with the wicking up from the bottom. As you're only exposing part of the medium at the bottom to the liquid, the volume wicked up will also be reduced.)
If you want a more decorative, opaque pot, do what I do:
- Buy a plastic pot with tray.
- Drill a couple of holes in the side, as in a semi-hydro pot.
- Using an aquarium-grade silicone, glue the pot to the tray, then plug the bottom drainage holes with it, as well.
If it's a small plant, you can take it to the sink and water heavily, tipping the pot (hole side up) to drain the tray when the reservoir is full and the pot has finished draining. If it's a large plant, I water slowly all over the surface of the medium, so it will absorb the liquid as it trickles down, and continue to do so until the reservoir fills and starts to overflow into the tray.
For those plants, knowing I won't be flushing thoroughly but a few times a year (I take them outside and let 'em have it with the hose), I feed at only about 50 ppm N.
Alternately, you can use the pot & tray as-is, using the tray as an external reservoir (buy a deep tray), but I avoid that as I have pets that might think the trays of my large tropical plants contain drinking water, and it's way too easy to overflow and spill!