Interesting! Have you seen this post: http://forums2.gardenweb.com/forums/load/contain/msg0716420723634.html?3 ? He used rain gutters to set up something similar but different.

To keep an eye on the water level in self-watering containers, I saw someone suggest a cork with a flag on top. Since it floats, you can see the water level easily and refill when necessary.

I bought some smaller self-watering pots this year and I can definitely tell that they make a difference but I'm sort of intimidated by all the tutorials for making your own so I've been trying to figure out a better way for next year. I'll be watching your experiments closely because that doesn't look scary at all! :)

My first thought was something a lot like his gutter system. I was thinking of two 2x4's, one either side of the sewer pipe, to set the pots on, but it occurred to me that, if I set the containers beside the pipe, I could double the number of containers. I built a self-watering horse trough planter yesterday, and I'll probably use the cork and flagged rod to alert me to low water in it, since it's filled through a pipe, and I can't see the water level.

The nice thing about the sewer pipe system is, I think, that you can make it any size or shape. It can be shorter, like six feet, and still be worthwhile. Or it can be 300 feet, if you can keep the pipe level enough that both ends have enough water. Or square.

How large are the pots you're watering this way? I really am intrigued! Wonder what my folks would think if I asked for 10 feet of sewer pipe for Christmas! Lol

They're about 3 gallon pots. About 9 inches tall and about 10 inches across.

Thanks! I have LOTS of pots that size! This year I'm growing cucumbers, peppers, and basil in those smaller pots (and even some watermelons that unbelievably are doing quite well but I won't be doing them in such small pots again!) I also have 18-gal and 31-gal tubs that have different things (mostly multiple plants) in them. Do you think the same concept would work with two (or even three for the big rectangular boxes) wicks per container or would it just drain the reservoir too fast? Or would this kind of wick even be able to support that much soil? If I try this, I would probably be limited to a fairly short pipe (6-10') but could go with a bigger diameter if necessary to hold more water. I'd just need to figure out how big of a diameter. I am planning to do more "small" stuff next year so I could just do something like this with the smaller pots and figure out something else (or keep winging it like I am this year!) with the bigger ones. My mind's just racing...

I'm trying a galvanized horse trough right now, using twelve rope wicks, and I know plenty of people do them with 4-inch pipe stubs that extend from the soil compartment down into a water space in the bottom, using the soil in the pipes as wicks. They tend to use a lot of those pipe stubs. I'm trying to see if enough water will disperse through the soil well enough from four clusters of three rope wicks running up through tubes.

So, I think it's not exactly whether or not it will drain the reservoir but whether you are able to keep enough water in all that soil for the plant demands. Mature, fruiting tomato plants may need anywhere from 2 pints to a gallon of water a day, depending on conditions. Six feet of 4-inch pipe holds about 15 gallons. In my system, the maximum capacity for six feet of pipe would be twelve 3-gallon pots. That would require daily refill at the absolute worst cast, and I would expect to go two or three days between fills.

I don't see any difference between a 36 gallon tub and the twelve 3-gallons, assuming similar depths of soil, and my latest observation suggests that I may need to raise the pots a bit. Right now, the wicks lie in the soil about one inch higher than the water level, and that may be pulling a little too much water into the pots.

Keep in mind that this is all experimental. I might well end up going back to my original notion or a single row of pots above the pipe, if that wicks more properly and makes the reservoir last longer on a single fill (assuming I don't automate the filling). Can't tell yet. There is considerable difference in moisture depending on how far the probe ends up from the rope wick. I'm going to try some different things and report on the blog.