apartment therapy changing the world, one room at a time

The concept is that the plant absorbs the right amount of water it needs via the inner clay pot...and the unabsorbed water starts to grow algae and mold and smell bad?

Unfortunately not all house plants like damp soil. Actually, MOST of them don't, like Dracena or Peace Lily. We happened to learn this the hard way - lost a couple of plants after moving them into self-watering pots.

But it works very well for violets. It's the best way to water them, since they don't like to get their leafs wet. I always leave them in a shallow tray with some water whenever I go on vacation. Glazed pots do better on a long run as they don't get moldy - terraccota pots [with holes in the bottom] DO!

Yup, as long as the terra cotta pot is not painted and glazed, then water would go through.
And instead of using a glass pot, you can use any decorative pots (without holes, of course). I think that way, you limit/emilimate the algea problem.

I have two self-watering pots, and my gerbera daisies are still growing (1 year old and one's about to bloom! :)

Ferns love self watering pots. I have had two pots for over a year and they have never smelled or grown algea. Karim Rashid's Grobal is brilliant. It comes with a coconut husk potting soil that doesn't rot or grow mildew.

http://www.velocityartanddesign.com/product.php?productid=20404&cat=1069&manufacturerid=&page=1

I'll take your word for it. I have very severe mold allergies (most of San Francisco gives me a head cold), so I'm very hesitant to provide the evil little spores any chance to flourish.

Here's a similar self-watering pot. Instead of having the inner pot submerged in the reservoir, the pot sits on *top* of a glass reservoir. Water is wicked up through a nylon string.

http://www.evasolo.com/products-flowerpot.html

Haven't tried it myself. Not sure if it will encourage algae growth.

I have another warning about self-watering pots.

Some of them work by using a plastic grid/net, of sorts, to suspend the plant over the water receptacle.

I had a beautiful fiddleleaf ficus that got so big that the roots grew out the bottom. I had to yank the pot apart and rip off the plastic grid when it came time to repot. It did a lot of root damage.

The ficus lived though, and in fact, now I have the same problem again, only now the roots grew out of the new pot into the earth. Apparently I forgot to put the saucer under the plant, then didn't notice when it started looking suspiciously healthy. I can't believe I made the same mistake twice. I hope you will learn from my errors.