I have a post under Greenhouses asking the same thing: anyone have a setup using a Walipini (pit) greenhouse? Would like any feedback, tips and dimensions please. Having the pit dug out tomorrow and stuck on the size. I know I need to determine the size of the system but I was hoping to back into that once I decide on he greenhouse. I'm in NW Arizona zone 7A. A few days in the 90's during the summer and winters can get down to -10f but doesn't stay there long. Not sure if I can get away with having Tilapia but am leaning toward them. I will be building the greenhouse with earth bags so hopefully I will not need a second heat source.
Anyway, I would like to have a DWC bed, wicking bed and traditional gravel bed. Would like to know if I need to go wide with the greenhouse or keep it narrow and long.
I would say that is probably a matter of what you want it to be. Keep in mind how far your arms can comfortably reach, the size of your grow beds and tanks, and the space that you need to comfortably maneuver and work in the greenhouse.
Sounds like the cold is your primary concern. I'd encourage you to read some of the stuff posted on my blog (see signature). A wallapini is a great idea, though there are cheaper and easier things you can do to reduce your heating costs.
You don't have to limit yourself to one fish. If you can get 7-8" stock, you can raise a winter fish and a summer fish. Zone 7a would allow you to raise tilapia year-round if you had a well-insulated, air sealed setup in a good greenhouse.
Thanks Jeremiah for your feedback. I am familiar with your articles and blogs. I also get the ASC mag. Using freezers make good sense, and insulating the rest. Not sure I can find a freezer the size I need though.
I think the Walipini will work out. I am sure I will still need to supplement heat in some way. Not sure about the fish. Plan to harvest also so would like little to no bones and easy to clean. *I know I'm asking a lot
My big problem now is construction costs on the south wall/roof. I was planning on building a rather large greenhouse (40'x55') which would make my vertical distance on the south wall/roof around 45' based on the angle I need. Can't find anything economical to span that length for framing.
Location: Madison, WI
posted 6 years ago
Awesome - glad to connect with you!
Wow - yeah that's a big span, depending on your snow load. Is there a reason you're opposed to support posts?
With the way this is totaling up the $ I am not opposed to anything. Originally I just wanted to keep it clean and open. Posts down the center would be fine. That still is a lot of lumber.
Btw: Solexx for that roof would be over $5k!
Location: Madison, WI
posted 6 years ago
Yeah Solexx is Cadillac. Cheap option is single-wall poly supplemented by pool cover in winter. Kinda chintzy but it does the job. For double protection, you could do low tunnels over grow beds.
I'm in NE arizona at 6000 feet.
I come and go but the three months i spent there in the summer gave me the firm opinion that food growing has to be in a controlled enIvironment, the pit greenhouse.
My pit is four feet deep, eight wide and about sixteen long.
The shelves are three feet wide the length of each side.
So fourteen wide by sixteen. The shelves are for hydroponic trays made out of two by sixes and sheet plastic. I might trim them down to two feet wide cause that eight feet is narrow.
I am thinking,THINKING, that i need a plywood roof.
I don't know that the coolness of the earth can overcome the roasting summer sun. So i'm looking at eight by two panels that would open up like butterfly wings. Painted glossy white to reflect the light but from nine am to four pm no direct sun.
Half the panels facing east and half west.
In the winter it all needs to be tight and originally i thought clear plasic but the sun degrades it in a year.
Just a couple days ago i started to wonder about a two liter soda bottle cut into a rectangle and laid flat like shingles..
I don't have money but when I'm out there i have lots of time.
The fish tank(s) would run along the center line. A solar panel wired to a small boat bilge pump works when the sun shines. Fish poopy water to the trays and back again.
I would love to do tilapia but i think that will involve a water heater.
So the fourteen feet wide is related to the length of the plywood roof. The pit can be extended as i have the energy.
I would like to dig deeper unless i hit hard clay. The problem is the flinging dirt out of a four foot pit is a whole world of difference from a five foot pit.
This picture was early days. Later pictures include some of my carpentry and I'm not ready to show that.(disaster )
I'm STARTING what will be two walipini, and have water table issues so I'm doing massive berm to help deal with the 'tie to the earth' and keeping things where I can handle the occasional back-soak issue. My soil is pretty close to adobe clay, with blowsand. Being that...
I'm aiming for 20x75', and two. One to be more of a four season 'abode' with my citrus and zone 10b tropical (fig, date, and various colocasia and alocasia); and a RMH for supplemental winter heating as a lot of those frown at 50f or lower. I also want to keep a few wormboxes and some aquaculture in there (spouse is into fancy goldfish). I spent a winter in a freestanding greenhouse shell inside my shop, and kept a two stage goldfish setup to provide 'used' water for watering, and kept a reservoir of a lift (350 gallons) of 'seasoning water' (heat reservoir and to degas as it was city water supply). Reservoir provided water change water, used fish water was used to water plants (some under lights). I wish to expand onto that.
Other walipini will be mostly for food propagation, and for starting small plants seasonally. I'm told a 75x20 can provide for a family of four to six. That one will also have an RMH. My biggest costs so far will be the insulating blanket for over the plastic. I sourced lifts that never had pesticides in them; posts, poles, and beams to build the cap structure; saving for my sandbag bags right now to do earthbag inner walls, and for the greenhouse sheeting for the cap.
Long, but back to topic. I fully plan to have at least one integrated with fish as part of the system, to produce nutrient enriched water for the plants. Something to eat would be nice but I'm afraid hubby's hobby means more decorative. However some of the plants will be eaten! You might narrow your walipini some, I'd say it would take structural steel to span that much, Jim. Literature and such that I'm referring to are doing the 20 or so foot wide, and I was able to score old telephone poles and some old barn beams to build the capping with, I will have some central support posts going down the middle. Let me know how you're doing Jim, Kevin, and the others! (yes I'm blessed with a quarter acre facing the sun and it has mounds of fill dirt already to begin the back banking. I plan to terrace that for growing small trees and seasonal plants...)