EarthTainer 2 versus 3 thoughts

[SaberTooth]

I've been thinking about the new earthtainer 3 design. I like the idea of the limited waste material and the double walled benefit to reduce heat on the roots. I just have a concern about the strength of the support around the wicking basket holding up after soil is added and am wondering how sturdy the pea fence would be attached to the top of the container.

Having said that, I am almost finished building three of the E2s and am thinking about a modification. Instead of throwing away the top portion of the container used to create the airation bench, why not cut the top lip down about an inch and drop the rest into the main tainer to form the double wall? I was thinking about using 4 bolts with spacers on the long sides to prevent the colapse of the inner wall when soil gets added. Would this be an improvement or not? Would it be better to leave the seperation or put some type of insulation between the two walls?

I intend to try some pretty vigous varieties this year and have concerns about the glamos cage design holding up and not bending at the legs and falling over due to the weight of the cage extension, plants and fruits. It is my experiemental year with containers.

Thoughts?

[rwsacto]

I think Raybo has hit another home run with this design.

Assuming that aeration and insulation (space) is a benefit of the double wall, I agree with adding spacers to the wall bolts to maintain space at the top between the long walls. I would also suggest that with the E3 design, additional air holes can be added to the sides of the inner wall to further improve media aeration (ala smart pot or air pot). I don't know if too many side holes would inhibit wicking, and landscape fabric may need to be extended up the walls. There must be a balance that is just right. Anyone want to trial this?

I share the concern about the cage supported directly on the container wall. The downward forces are concentrated in discrete spots and thermal and wind oscillations could cause early fatigue cracks in the plastic. I hope my concern is groundless.

I plan to build and modify an E3 to use removable glamos cages like my E2's to see if it is a viable option and does not interfere with the bench support.

Rick

[rnewste]

Hi Guys,

I truly encourage all to experiment / improve the EarthTainer design. Regarding the cage sitting on the container's rim, I believe the 12 "hard-points" will balance the load of the fruit and distribute the downward force across the container, not just at a single point or two. Also, when the plant starts to load up, I don't see wind oscillation to be much of a problem. If it is, see my recommendation and photo in the Guide of using 2 Tarp Tie Downs at the diagonal corners.

To increase the air gap along the sidewalls, you can simply use a 1" long screw and put 2 or 3 fender washers as spacers between the outer container and the Aeration Bench. This will give you a pretty constant air gap all around the sidewalls. Personally, I think there are enough air gaps now at the corners and along the handle ends, but the spacer approach will certainly do the trick.

Regarding adding more aeration holes, there are already 342 holes in the surface of the Aeration Bench now, so I don't believe adding more along the sidewalls will be of any benefit.

Rick, I am very curious as to how you would make the Glamos cages "removable". I've got 30 of these cages I am now planning to donate to the local Community Garden, as I couldn't ever figure out how to make them easily removable.
Raybo

[rwsacto]

Hi Ray,

Here is what I did. (First, I apologize that the photos show a SWC from a single container using the lid for aeration bench and not a true Raybo E2)

Photo 1:
I took 1/2 in. PVC and made 8 support tubes. Each tube has a slip on cap on the bottom (no glue) and small holes top to bottom to provide aeration and drainage. The tubes go through the bench and are spaced for twin 4 wire cages. The photo show caps on the top. I learned (the hard way) to do this when putting the aeration bench in the container and adding the media. It makes these tasks much easier. The landscape fabric needs to be pierced to slide over the cage tubes and fill tube. The downside is this provides more penetrations for roots to slither through. Another trick is to put rubber bands on the tubes just above the fabric before placing the aeration bench into the container.

Photo 2:
Add media, align the tubes vertical and remove the temporary top slip caps. Once the media is added, the tubes are very stable.

Photo 3:
Plant tomatoes, centered for each cage. Note also I am using a cut trash compactor bag for moisture retention and shading the container. These are more rugged than regular trash bags. I also painted the top rim with plastic spray paint as sunblock for UV resistance.

Photo 4.
Add cages when needed. Once inserted, there is very little play in the support. I connected the twin cages together with zip ties. These are 18 gal SWC's and supported twin, double high cages just fine. The container will probably fall over in high winds before the cages come out.

Late in the season, I removed one tomato plant and one cage from a SWC. The remaining solo double high cage bent over in a windstorm. I just straightened it back up and it stood by itself until take down in December. None of the SWC's with twin, double high cages had a problem in the wind.

I did 4 SWC's like this last year, each with twin, double high cages. I will convert the rest of my SWC's to this system this spring.

I hope this helps, especially that after seeing that picture cleaning out the "caged" E2's. Feel free to use any or all of this in your designs. Let me know if I can be of further assistance.

Good Luck,

Rick

[SaberTooth]

So the cages just slip right into the PVC and sit on the bottom of the container? Are you saying that without an anchor to the airation bench, the wire cages have some "play" in high winds and are less likely to bend and last longer? I suppose they would be more convenient for storage too. And just for clarity in the first photo - is that two wicking basket in opposites ends of the
airation bench?

This is an interesting twist and would save some $ on the wire anchor ties. Thanks for posting the photos. Now you really have me thinking about doing this to the three I'm in the process of building.

[rnewste]

Saber,

Yes, I too am interested in how Rick secures the cages to the container so the weight of the tomatoes doesn't "rotate" the legs of the cage out of the PVC tubes as the tomatoes load up.

I also look at design simplicity and time to build the EarthTainer. The new ET3 design assembles in quick fashion. To be sure, one could adapt the lid to function as the aeration bench, but how much time is invested to make these modifications? If it is minimal, then saving spending $13.00 for the second container is worth it. How much offsetting this $13.00 was spent on the additional PVC pipes, caps, and other added parts? Also, how stable is the lid aeration bench when loaded up with wet potting mix?

Regarding the wire rope clips, they are actually pretty cheap - 17 cents each from the Link in the Guide.

Keep the design ideas coming!!

Raybo

[rwsacto]

Originally Posted by SaberTooth

So the cages just slip right into the PVC and sit on the bottom of the container? Are you saying that without an anchor to the airation bench, the wire cages have some "play" in high winds and are less likely to bend and last longer? I suppose they would be more convenient for storage too. And just for clarity in the first photo - is that two wicking basket in opposites ends of the
airation bench?

Hi guys,

The cage wire slips right down into the tubes and rests on the slip caps sitting on the bottom of the container. The cage tubes penetrate the bench. I am only saying my twin cages (double high), when zip tied together, are stable and don't sway much or lean once in the container. They are not fastened to the container and can be removed by lifting straight up.

The bench is cut from the lid. It is supported by 5 lengths of 3 in. PVC drain pipe. Two of the pvc lengths on opposite corners serve as a wicking chamber. A "basket" is made from a length of drain liner normally used to keep dirt out of this type of drain pipe. I zip tie the liner bottom together and zip tie the top edges to the top of the pvc support. (Disclaimer: I think I found this bench design concept on the internet :-) )

1/2 inch pvc pipe is about $2 per 10 ft and it takes about 12 ft total per SWC. Slip caps are about $.25 each. Total material cost is $4-$5 for the cage support.

The 3 inch pvc drain pipe is about $.40 per foot so about $1 for bench support. maybe $1 worth of drain liner for two wicking baskets. Time to assemble may be longer and a bunch of zip ties are needed.

The E3 may still be a superior design and sturdier with the simple assembly and double wall.

Rick

[SaberTooth]

Ray - Point taken on the $.17 per wire clip. However, to get this price, you have to go mail order since they are more than double that price at either Home Depot or Lowe's. Having to go mail order on the wicking basket and clamps are the only things that are not easily obtainable for me - but I get your point.

I like the concept of the PVC under the airation bench acting as both support and wicking basket - that's a good idea. I just wonder how the system would compare against the basket.

I think I'm going to try and combine the best of your ideas. I've already bought all of the material for three E2 containers. I will double line the containers instead of scraping the upper portion of the second container and install it to provide space between the walls (at least on the long side). I was also thinking about taking Rick's idea of the PVC tubes and extending them to the under side of the first ring of the tomato cages. This way I could zip tie the tubes to the ring and leg of the cage for a more sturdy support (essentially resting the cage sysem on the pvc support while still being removable at the end of the season). In the event I needed more support, I could run wire between the pvc and/or still use Ray's idea of the bungee cord on the corners or as an added improvement go up one size of the pvc and beef up the supports.

Thoughts? Fire away

[rnewste]

Saber,

If you go the route as Rick did of using the 8 PVC "guide tubes" for the cages, I would simply use a couple of the Tarp Tie-downs to securely keep the cages rigid. I'm just concerned that gravity alone will be too fragile. With tomatoes loading up typically on the sunny side of the EarthTainer, I would be concerned of this imbalance torquing the cages out of the PVC guides.

Regarding the wicking basket, you can get the 5" Net Pots at all Hydroponics Shops. Alternatively, you can use a mid-size Deli container. You will need to drill a dozen holes in it to let the water in:



Raybo