How about setting all of your pots on top of some type of blocking within the confines of a child's wading pool or other large container, the blocking serving to raise them above the effluent that will collect in the pool/container as/when you water?

Al

That would work, but my idea is to keep the setup in place even while I am home. For that reason I would like the setup to be rather inconspicuous.

My plants are all sitting on the windowsills to get as much light as possible (I live in an apartment and have no yard), I'm thinking to pass the drainage hoses behind the pots and down behind a radiator to keep them mostly hidden.

Currently the pots are sitting on saucers (that seems to be the word, time for more googling) which collect the excess, but they have to be manually emptied after each watering.

Henrik

I put small pebbles (pea gravel or any ornamental pebbles) in saucers & the pots are sitting on top. That way they never sit in water should any collect in the saucer.

Maybe a longer & narrower tray accomodating few pots with pebbles would work on the windowsill? ...just an idea...
Any water should evaporate, which would add little humidity to your room & plants.

Are you planning on recirculating the water back on plants?Rina

Recirculating the water is probably not a good idea - just in case that's a consideration. The volume of water that evaporates + the accumulating salts flushed from the soil soon skews the ratio of nutrients in the effluent and increases the concentration of dissolved solids.

Al

Al, that's what I thought (about re-using the water) - glad you mentioned it.
Rina

You could probably find all that you'd need from an industrial plastic supplier like US Plastics (http://www.usplastic.com/)but you would need to do some modification and fabricating to do what you want.

With gritty mix you could create a flood and drain type or drip type of hydroponic system with a pump on a timer that you could run all the time whether you're home or not but following what Al has said you would need to watch out for the increase of the dissolved solids in your reservoir which would really amount to just changing the water very 4 to 6 weeks and topping off the supply in between changes.

In simple terms, your pump clicks on and water cycles to the pots for a predetermined period of time, it drains through and out of the bottom and back through the drainage system to the reservoir. The pump clicks off after a few minutes and the water stops flowing and drains out of the pots as usual.

Hello,

I did not consider recirculating the water for the reasons mentioned above, but the excess still needs to be led away. Such a feature would be desirable even without an automatic system to reduce the work needed to water the plants. Right now I have to lift each pot to the sink to pour out the water accumulated in the saucers.

Rina, I don't think the evaporation is quick enough to remove the amount of water that might flow through the pots. Of course I can regulate the flow, but I also want to flush the soil somewhat to prevent gradual buildup of salts.

That's why I'd like some kind of saucer which I can attach tubing to.

It seems like I might have to modify an existing plastic saucer as mentioned by dellis326, but I'm not sure how to best do that. If I cut out a hole I would need to make a water tight seal somehow.

There are a number of ways you could connect the tubing to your drainage saucers. One way is to use hose connecter fittings in which you need to drill a hole and screw the fitting on. Can cost a lot if you plan on doing this to a lot of plants.

Another way is to drill the hole slightly smaller the the plastic tubing, lets say a 7/16" hole for a 1/2" tube, or if you're in a part of the world with a more sensible measuring system 12mm tubing with an 11mm hole, then take silicone aquarium cement and lubricate the end of the tube and squeeze it through the hole. Let it set up for a day or two and your ready to go.

Just make sure the size tubing you use will drain the water out fast enough so it doesn't overflow.

It seems like I might need what's called a "bulkhead fitting" or "bulkhead connector" to go through the saucer. I just need to find some with suitable dimensions.

A bulkhead fitting/union/connector will work. You will need to have hose barbs to transition from the threaded outlet of the bulkhead fitting to the hose. Another way to go would to just use hose barb X Male pipe thread adapters and find some pipe locknuts and use two for each adapter and skip the bulkhead altogether.

Thanks for the help dellis326,

I have very little experience with all these piping/tubing terms.

It seems difficult to find many of the items in smaller dimensions so as to fit the smaller sized saucers. Also, at those smaller dimensions the draining capacity will be severely reduced, as well as the buffering volume of the saucer (requiring more controlled release of the water, in order to avoid overflow).

I'm thinking to perhaps connect the drainage directly to the pots instead, and seal the drainage holes. The pot will then serve as a bigger buffer, and also allows for larger fittings to be used (since the saucers have a limited height).

The issue then becomes to seal the drainage holes well (which should be fairly simple), and to find some kind of filter to attach to the bulkhead fitting (so that no soil particles run down the drain).

Well, and the repotting necessary to install everything...

Seems like there is no easy way out :)