Earth boxes use 3 gallon reservoirs and Gardener Supply boxes use 4 gallon reservoirs.

Basil and peppers will not use water as quickly as tomatos or curcubits.

I had 2 indeterminate tomatos in a few different GS boxes (4 gal reservoir) and had to fill up daily, but had 6 peppers 2 hot, 4 sweet) in an EB with 3 gallon reservoir and at most filled it every 2-3 days at summer's peak.

I have no experience with a deep reservoir so don't want to speculate on that. You may have to water more often as you are in a warmer climate than I am.

You won't have soil that is too moist if you use a coarse mix. When using self waterers you don't want the reservoir going dry at any time ideally. How wet the mix will be is dependent upon how much water it can hold. If you used garden soil and compost it would be very wet and probably get stinky (lack of air) before long, but if you use a mix of say 50% peat and 50% perlite you would be fine. You would also be fine replacing some of the peat with pine bark fines and if you can find Turface MVP it is nicer in a self waterer as it holds more water/wicks faster (perlite is fine though).

Thanks for the response. I know basil and peppers wont use as much water. 1/2 of the reason I am going with the large reservoirs is to avoid a lot of cutting an measuring. Using the full Sterilite container for the bottom saves me a lot of construction time, raises the plants up for more sun, and the lid for the bottom container(with a whole in the top) supports the structure.

I was going with the premium potting mix (compost, peat, perlite IIRC) from OSH to fill these. Now I think I will mix that with some Turface MVP, thanks for the suggestion.

As I was thinking more about this, I will plan to flush the tanks monthly. Before I refill them, I can let it sit empty for a couple hours to get some more air to the bottom of the wick. Hopefully that should keep the mix happy for a few years.

The climate here probably won't cause me to use too much water. I am about a mile from the coast and barely saw summer temps break 85. It's one reason I was so surprised hearing people refilling a 3 gallon tank that often. I guess I should grow some tomatoes next year. Most of the summer I watered my standard pots about once a week. I know some could have used more, but I didn't lose a single plant.

As I was thinking more about this, I will plan to flush the tanks monthly. Before I refill them, I can let it sit empty for a couple hours to get some more air to the bottom of the wick. Hopefully that should keep the mix happy for a few years.

If you are using potting mix for the wick you do not need to worry about it's condition at all. The only purpose it serves is to wick the water upward and everything else being equal the more broken down it is the faster it will occur.

Common advice when filling a container is to not tamp the mix down, but just water it in. This is to reduce compaction. This advice is reversed when it comes to filling the wicking chamber with potting mix. In this case you want to mash it down firmly so the particles make good contact with each other. Best to prewet the mix as well so it mashes down even better.

This distance the water has to travel before it makes it to the growing area of the mix is considerable with your design. I would recomend testing the design this winter and see if water wicks efficiently, particularly when the reservoir is near empty. If not you can try using a different mix in the wicking chamber. Peat works exceptionally well in the wicking chamber. Basically the qualities you want in the wicking chamber are the opposite of what you want in the growing area. Your wick has to overcome gravity and if you need the water to travel upward 12" before contacting the growing media you want a water sponge. The climate here probably won't cause me to use too much water. I am about a mile from the coast and barely saw summer temps break 85.

Oh, you will be fine then. Most of the folks reporting having to refill the EBs 2x/day with tomatos are dealing with hotter and drier conditions. For me it was never more than 1x/day with a 4 gallon reservoir and that was with 6'tall plants, unpruned and bearing fruit.

Hi Zander,

I'm in zone 10 (Fla) and planning a similar setup...18 gallon round tubs (Home Depot - Pioneer Plastics) and a 5 gallon reservoir (Sterilite #1626 basket - Target). This setup may be problematic as I'm looking at 10-11 inches of wicking depth from the top of the reservoir. Can you give me a progress report on your experience?

Tom

Hello Tom,
Sounds like you found an interesting combination. I found that a 3.5 gallon paint pail in a 5 gallon was easy and quick to assemble. The reservoir is only about 7 inches and I am using nylon stockings with coconut coir mulch inside for wicking. The potting mix doesn't sit in the water at all. I'm growing peppers not tomatoes so they use a lot less water. So far the results have been amazing. Some details and pictures are in my Manzano thread.
-Zander
P.S. The 3.5 in a 5 idea came from a DIY self-watering document floating around (Thanks Joe from NJ)

Here is a link that might be useful: Manzanos in Self-Watering Containers

Jo,

Very interesting. Thanks!

Questions:

1) What's the diameter of the wick and how long is it for the size pot your using?

2) What soil mix are you using?

Is anyone still on this?? I have several 32"x32"x32" fiberglass containers we are trying to set up with self watering component. I noticed in some Youtubes the use of 6" perforated drain pipe with the water resevoir reaching the 5" mark to alow for root pruning via the 1" air space. Has anyone here used this idea? Apparently they also use socks which I guess would be the wick. But I have also seen them use the drain pipe with no wicking material. Just curious to know if anyone have been playing with this and come up with happy results using these methods. My resevoir is only 7" tall but holds 6 gallons. I was pretty excited by that fact...and wonder if I can just lay the drain pipe in there, drop the water level an inch..and be good to go?

So alot has happened since I first inquired. I now have a holding capacity resevoir of 25 Gals for the 32" cubes. This will allow a much smaller albeit still holding capacity of a 100 Gal grow bag for the top portion. Is there a problem I should foresee coming to have that large a resevoir of water? It will be mighly hard to remove the plant monthly to "clean" and I"d rather not have to do that. I am submerging drip pipe with sleeves to take up all but an inch (for air space) in the bottom. So the wick would be the sleeve connecting with the grow back for wick. Sound like a plan?