Kyle Neath wrote:Hey Dan! I think you picked a great forum. I also added it to the soil forum as that seems relevant too, I hope that helps.
As per your question, what you're dealing with sounds very similar to most suburban plots: growing on fill dirt. I've seen no end of successes in this context, so with enough effort and time I'm sure you can grow plenty of vegetables. If possible, I would suggest trying to save the topsoil from excavation and replacing the top layer with that topsoil. That would be the best of circumstances, but even if you can't there are many options. My personal suggestion would be to look into importing compost and mixing it into the top layer of the woofati (or just layering the compost on top too). Otherwise you can chase slower paths: growing cover crops, holding animals, compost/mushroom teas, etc. The goal will be to increase the organic matter and soil life in the bermed soil.
S Bengi wrote:As a general rule, I would just add
1) water management (water bucket/irrigation pipe/sump pump)
2) soil life (compost/worm tea/mushroom slurries)
3) carbon (compost/woodchip/straw)
4) mineral (rock dust/azomite/compost/etc)
But even if you didn't do any of those things your plants will still survive, but why just survive when you can thrive, you already did so much work already just complete the process.
Joshua Parke wrote:
After I run it I empty the brew into a larger barrel and then fill the brewer with fresh water and use a brush to scrub the inside, then dump that into the barrel so I can get as much of the sediment out of it as possible. I scrub it with a brush and fresh water after I finish with it, and run hydrogen peroxide in it as well just for good measure, but I don't fill it up all the way for the final scrub/cleaning. And I don't use the hydrogen peroxide water with the finished compost tea. The hydrogen peroxide will break down to water and oxygen, or something like that, so I'll use it to water with later. I keep the air pump on until all the water is drained.
Mike Phillipps wrote:Sorry for the late comment.
Dan, your math looks right.
My analysis is indicating that the water tank shouldn't be insulated because it's better to have the added thermal mass of the soil and groundwater if any.
I was surprised to discover that thermal diffusion in still-water or wet soil is actually *lower* than dry soil! So in theory having wet soil is better than dry soil because it actually *decreases* the rate at which heat diffuses away, although only if the water isn't flowing through the soil in the particular time-frame of interest.
Nick Kitchener wrote:I only just found this thread so this is possibly too late...
Did you run some math regarding thermal uptake of the water mass vs thermal loss of the greenhouse? It usually works out that you can't efficiently transfer enough heat from a hot greenhouse to the water during the day to completely offset the thermal loss by the greenhouse at night. Remember that not all days are cloudless...
What happens is that the system "runs down" to equilibrium over about a week or so. Here is a video explaining what goes on:
David Maxwell wrote:From what I have read, the main heat loss in small-scale greenhouses occurs at the edges of the curtain, which needs to be sealed. So, multiple smaller curtains suffer from the problem of multiple edges. Hence a single wide blanket is preferable..
How best to seal the edges? Neatest way I have seen is to fasten magnetic tape to the sides of the curtain, and build ledges along the outer walls to support the edges, also equipped wth magnetic tape. The two magnetic tapes will automatically align themselves, avoiding the issue of the roll getting off-centre. The long section of curtain is supported by wire cable stretched parallel with the joists, (metal clothesline has been suggested). The designs I have seen urge the incorporation of weights to maintain an equal tension on the wires so they don't sag as the temperature rises, but I am not convinced an 8 ft. length of wire is going to change in length that much. Have any of you any experience here?