I'm throwing this out there for discussion, spawned by a recent blog, but something on my mind since first being interested in AP. NO PUMPS. Can it happen, and how?
Why? Well, 'cause if we didn't need pumps or electricity we probably wouldn't use them, and AP might truly join the ranks as a sustainable food production method, and applicable to feeding the poor, saving the world, yada yada...and at the heart of it all, I'm cheap and lazy. I find personal victory in reaching the end goal faster, smarter, easier, cheaper than "how it normally done".
The only thing that comes to mind is a wicking bed of some sort. And I need to consult my book of wild ideas before I open my mouth.
Now I won't be a stickler about including some pumps using waste energy, or some low-tech mechanics, or human power, but try to avoid solar PV and windmill electricity (not that they are not excellent, but they are being done and discussed elsewhere).
Pics, sketches, links, etc are always nice. Happy brainstorming.
Instead of talking to everyone individually in this thread I would like to bring up general points (if I may).
First, we should all remember the law of conservation of energy! (!!!) That annoying part of physics that makes me hot (get it, it turns into heat energy?) and depressed, because the universe as we know it will be destroyed. (!!!) Anyways, tinfoil hats aside, permaculture may hold the answer to this question. I remember reading a book by a Aus. Permaculturalist who built a giant pond, and put some trout in it. The pond was in her modest yard, and wasn't that enormous, either. Through diffusion, or osmosis, whatever, it would water some water-intensive trees, most of them tropical. Then, she had semi-aquatic plants for filtration. This is a traditional pond set-up, with some added temperate tree benefit.
The way to improve on this is to remember that the Chinese already figured this out (or the Aztecs, whichever design you want). When we first learned about hydroponics or aquaponics we get the "ancients are all knowing" or "ancient technology is analogous" bit from websites (or at least I did). The Chinese used a available source of water to irrigate crops in the Southern part where this normally took place. This would create a pond for growing rice (a rice paddy). Some guy figured if you put carp in it you could get two crops out of one. So, they did. The practice spread throughout Southeast Asia. So, you could think about re-engineering rice paddies with other crops. This practice is, still, very common.
The Aztec method, however, is more familiar and simpler. Make a floating raft bed. What they did was ingenious. Banished by the dominant civilization to the swampy islands of Lake Texcoco (now Mexico City) they had to find a good food system. So, they gathered reeds by the shore and put the lake bottom onto it. Then, they put it out onto Lake Texcoco. So, you could just replicate this with Styrofoam, or reeds, and use net pots (yogurt cups) in your own backyard. Now, this isn't aquaponics. This is pond culture. You should always keep the stocking densities low, and I suggest using the dual root zone method with the plant, to keep nutrients at a good level.
Another idea is, well, similar to the one above, except it is a smaller, contained system. The now gone New Alchemy Institute had various ideas about greenhouse pond culture. Most of the experiments failed. But, the idea is like the one above, but aquaponics sized. The way I would think it would work is if there is a polyculture to break down solids, and a large surface area to tank volume ratio. I could see catfish and shrimp, or the like, eating from the same waster streams. Basically, you feed the catfish, and the shrimp (but less) and the shrimp will subsist mostly on algae and catfish "by-products". This could be further broken down by bacterial action, and the occasional clean every so often, to prevent solids coating on the roots.
Anyways, I hope this discussion comes to a theoretical conclusion and a test, or just a test. I love empirical data. I hope to see some!
(Sorry for the long post.)
@Chris: Thank you so much for your kind words. You give me too much credit.
I quite enjoyed reading ideas from all of you in this post. Sorry I can't reply to each of you individually.
I like long posts. . . (if, unlike my babble theyare wellthought out and meaningful). ;)
Eric Warwick will definitely be a major contributor in a few years. This young man researches and not only comprehends the science but actually sees the bigger picture. I can't wait until he gets funded and see what he comes up with.
Sustainable, natural farming is simply coercing nature to work in our favor.
It is relatively simple to use sunlight to power small, rather simple, self-sustaining eco systems i.e. moss or fern in a closed bottle. A larger example might be a small backyard guppy/ kio/ carp pond. However, extracting a full range of nutrients, esp. enough to sustain even one person requires a lot more water and biology than small confined harvesting systems like IBC totes can provide. There are two main factors that make AP not sustainable and those are; where and how feed is made and the other factor is the use of non sustainable/renewable energy sources.
So there are basically two types of AP systems. One being green-water/ pond culture and the other being artificial confinement operations (pool/ tank/ tub). As mentioned above, it will take a bit of water in combination with a diverse and mature eco system to produce food via sunlight alone. I'm not sure on the stocking rates of natural ponds that rely solely on natural inputs but it would be much less than artificial confinement where feed is a direct input. These natural (integrated multi-trophic bio systems) are maintenance free. No power requirements for pumps, aeration or lighting.
The next step up the tech ladder is intensive green water culture where food is made with the waste of another animal or the use of commercial feed. The only energy these systems use is electricity for aeration.
Another example might be; people in India and other third world countries commonly operate man/woman powered water pumps. As Eric mentioned terraced landscape on a south facing hillside could recycle nutrient rich water back to the top of their operation so that nutrients aren't wasted and labor is minimized without using non-sustainable power sources. Airlifts may be used in cases where there is a stream running through the property. There is an Austrian guy that uses airlifts and gravity to supply his trout with continuous clean water. Solar and wind power are too unreliable in most locations to be used efficiently unless mechanical storage is used, but this cost more so not applicable in most situations. Manual labor of one form or another is the only real viable option that I can see.
On the other hand, most of us live in urban environments that are not conducive to "truly natural", harvesting so require us to use artificial confinement. This type of food production in controlled environments can be fully automated or as low tech as ones budget, lifestyle and access to materials allows. These factors along with landscape determine what works best.
It just so happens that I have thought and looked into this theory too. This is what I came up with. Like you, I was trying to design a self sustaining, low tech system. I used someone else's idea of using medium diameter drainage tubes with the tops cut off and placed so that they are stacked on top of each other (fish tank and grow bed on top). The only difference is that I used half of the bottom tank (blocked off with a piece of plastic with holes throughout and indents on the top) to raise fodder fish and hopefully duckweed. The other half with growing fish. The drainage tube/growbed on top is simply a wicking bed system with either sifted soil or perlite/vermiculite. The idea here is that, mosquitoes and other aquatic biology would feed the fodder fish which would then depart from the safety of their enclosure and along with algae, feed our harvestable omnivorous fish.
The problem with this method and true for most soil based wicking bed systems is that there tends not to be enough air over time. Another problem with wicking beds that are constantly wet is that the micro herd maybe put out of balance which then becomes acidic.
Although he does use electric water pumps, Rick Welland, down in Mexico has a fantastic system that runs on deep water culture with a controllable, suspended raft. Ask him to share his design with you. I'm sure he would be glad to.
I apologize for not having time to write more than this babble. I can only hope to make it up during winter (my off season).
Cheers and good luck to all my AP friends.
You've inspired me to want to test it - no room at my place but my brother lives on a lake so possibly I can do something there - something more along the lines of the Aztec method. Thanks.
Eric Warwick said:
Anyways, I hope this discussion comes to a theoretical conclusion and a test, or just a test. I love empirical data. I hope to see some!
@Carey, thank you for your long posts! Whenever I see them I gain a little (or a lot) more knowledge. I think the AP system you said about a integrated ecosystem won't be truly realized until systems biology comes to be a mature science. We need to know how ecosystems work in a interconnected way. As far as I know, this requires a lot of drawing nodal networks, which is not fun unless you have a supercomputer do it! I'll probably look into Rick Welland's system sometime.
@George, fun! I heard word-of-mouth from an aquapon friend of mine that someone was using a lake with great results. I hope it pans out well. You should get a mass scale and record your vegetable biomass from it, If you're using dual root zone, tell us what nutrients and how much. Sorry, I get exited about experiment.
Hey Jon, here is a vid of a small working fluidyne pump. That paper I linked earlier gives the how and why's as well as the important math/design proportions. I know you were planning on incorporating an anaerobic bio-digester...maybe some of that methane could be used to drive such a water piston? Just an idea...
I also think the "permaculture" pond is probably the closest we are likely to see to long term sustainable aquatic/plant food production without much ongoing outside human intervention like pumps and aeration.
Problem is if you don't have the space for a fairly large pond yet you still want to grow lots of food in a small space, you are likely to need some way to do the extra work you can't give nature room to do on it's own.
Pumpless systems are going to be limited in the amount of fish and plants they can grow for human consumption.
Now you might get away with a pool, some water plants and bluegill with no additional aeration or pumping but you are not going to be growing huge amounts
I'm new here and to AP but, with many contacts in poor countries, I'm exploring the possibilities for those who are sufffering from erratic climate changes.
As you make aware pumping is the main problem in many places and I have been studying water lifting as an alternative.
This has been done for thousands of years and very neat systems have been developed that we could adapt. I am working on an adaption of the Shadoof which has a counterweight to minimise the effort required and with these one can lift about 20 gallons each minute (about 70 litres) so it will be more than enough for most systems if put into an overhead tank!
What puzzles me greatly is reading that without pumping/aeration the fish soon die but no-one seems to have seen the need for a back-up to prevent such a disaster!
I can't speak for anyone else. In my case I would say that budget or the lack of it, is the major factor. A Shadoof or counter weighted fulcrum devise is a fantastic way to lift water a short distance at a relatively low vertical incline. What we need in AP to is how to get great amounts of water high enough to make gravity really work.
I believe in the power of bio diversity and the full use of integrating all aspects of "natural" behavior for our benefit. To that end, I hope to delve into animal powered mechanical/ pneumatic storage and micro generators using enhanced natural conditions which could be adapted to 9 or12 Volt DC ("local"use) pretty easily.
Look on Youtube for freshwater shrimp aquaponics. There is a guy on there with lettuse on floats over the shrimp in the bottom. Asian type. and there you go no pump no nothing.
Now the problems. Air. Poop. Feed. Bored to death.
I like the idea of better mouse trap but..........
1. If you built your bed a the same level as your fish NO Lift. Wind mill water wheel for circulation.
2. Nile river BC Before Christ. Flood fields evaporated. Repeat. Aquaponics yes or no?
3 Tilt the planet back and forth so the water washes back and forth through the grow beds. See Aliens for help with that one.
You said, "I started this thread was to eliminate the need for pumps at all"
I'm trying to help people who cannot afford pumps etc but need something like AP in their dire climate.
That means no water/air pumps etc but, from what I gather, this limits what can be grown to lettuce etc and few fish. Using water lifting it is possible to raise 20 gallons (up 9 ft) every minute. If you did this for 5 minutes every hour how big could the AP system be?
Don't forget we are talking about people who spend hours most days labouring in their fields!
Jon Parr said:
Hehe. I like the third option, Brad. I am in California, after all, maybe earthquakes could stir the water. Seriously, though, my entire commercial build here is designed on level beds, just to minimize pumping lift loss. And maximum surface areas to minimize/eliminate aeration need. My first beds here using floating rafts don't need aeration, but air would improve growth, hence the need for an air plenum under the rafts. Plus, if the rafts themselves don't need to float, I can forget that damned foam. That's another thread.
Graham, many folks run solar powered back-ups (or battery, or generator) in case of power outage. The more you have to lose, the more important that becomes. If your growing with flood and drain, the beds can handle several days with no worries, so a simple bubbler in the FT will buy you time to figure it out. Half the reason I started this thread was to eliminate the need for pumps at all, making it much less stressful in the first place.
I still haven't built my convection system, way too busy this month. And tomorrow I'm leaving for the Disney AP workshop, then the Denver conference, then camping with the family for a week. So it will be October before I can renew efforts there, which drives me nuts.