Very simply stated Compost Tea is a water-based environment wherein beneficial microorganisms are extracted from compost or vermicompost (worm compost) and multiplied by the millions and billions. Some form of agitation breaks the microbes free from the compost and they multiply because food, like black strap molasses, fish hydrolysate, kelp meal, humic acid, etc. has been added to the water, which at least one type of microbe digests. When one or more type of microbe begins to multiply in response to the food, other microbes respond to this growth and begin to consume these initial microbes and multiply in turn and so on and so on. For example the initial microbes are usually bacteria which are food for protozoa so the protozoa multiply in response to the bacteria. The end result is a functional feeding cycle or microbial nutrient cycle. I refer to this as a functional microbial consortia. This develops over a period of 12 to 72 hours or more and is then applied to the soil and plants. In the soil there are a number of organisms which function in basically the same nutrient cycle and zone. Once again, simply stated, there are substances released from the roots of plants which feed bacteria (& archaea), again the bacteria/archaea become prey to the protozoa and the protozoa excrete substances which are available to the roots as nutrients (e.g. nitrogen) thus creating a feeding cycle. Other compost/soil microorganisms of great importance are fungi. Fungal hyphae, are long branching strands which grow through the soil and serve to; bind soil aggregates together, help retain moisture, store certain nutrients, provide a source of food to certain other microbes, provide pathways for nutrient and moisture delivery, decompose organic material and displace disease causing fungi. There are also other types of fungi which do not grow (to my knowledge) in compost or Compost Tea which form a direct symbiotic nutrient exchange relationship with roots. This sort of fungi is called mycorrhizal fungi and there are many different species. The major microorganisms at work in Compost Tea are bacteria, protozoa (flagellates, ciliates and amoebae) and fungal hyphae if present in your compost. It is best to have a wide diversity of each of these microbes present. There are higher order organisms like nematodes found in compost and soil and occasionally these are extracted into Compost Tea but they do not grow nor multiply in the tea. Of course in the soil there are many other contributors to the nutrient cycle, like insects, earthworms and other animals. In its totality this is often referred to as the soil food web.
Fungal Hyphae (phase contrast)
All life is in a symbiotic nutrient cycle even down to the microorganisms contained in our gut that assist us to digest certain foods. Life, consumption, excrement, death, decomposition, life. You are what you eat and the same applies to plants.
It has been discovered that aerated Compost Tea helps to ensure the multiplication of mostly aerobic microbes which are more desirable in this application. Plus the aeration provides the agitation necessary to dislodge the microbes from the compost. Therefore most Compost Tea machines or brewers, as they are commonly known, involve the introduction of air into the water and compost.
Many Compost Tea users and producers have begun examining their brews with microscopes to see the microbes present. This ensures that they have the desired microbes in the right numbers and diversity prior to applying the tea to soil and plants. I am fairly hopeful if not certain that in the future when someone purchases a Compost Tea brewer that the kit will include a microscope. It is the identification of what is going on in this tiny universe where I find my calling.
Fungal Hyphae (brightfield)
[SIZE=+2]Organic Growing from a Microbial Perspective
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To come to a rudimentary understanding of how organic or natural growing really works, one must cast off previous miscomprehensions from the chemical model, that when we fertilize or add compost or other organic matter, we are feeding plants. This is not the case. With true organics one is feeding the microorganisms in the soil which convert organic nutrients into a form which can be assimilated by the roots of plants. According to studies, there are only a very few plant species capable of absorbing only a very few organic nutrients. Most plants are only capable of absorbing inorganic nutrients which are made that way by microbes which live at the root to soil interface, the rhizosphere. So the idea which you have, that you are feeding your plants when they appear to need nitrogen and you feed an organic fertilizer deemed high in nitrogen, is bogus. You are feeding the microbes which feed the plants.
Chemical fertilizers, mostly derived from petroleum are inorganic and can be absorbed by the roots of plants, however they are pollutants, which can cause a die off of and population change of soil microbes [** see addendum below], build up unused residues which run into the water table and, in my opinion, create harmful tissue changes in the plants which humans consume as food and medicine. In addition, I believe, the use of chemical fertilizers promote the incidence of plant pathogens like powdery mildew, erwinia, fusarium, pythium, etc. The grower can end up in a vicious spiraling downward fall as they use one chemical after another to control the effects brought on by the others.
The plant is no passive player in the natural growing game of survival but is the master conductor of this delicately balanced orchestra. The plant receives energy from above the soil in the form of light. This photosynthesis results in the plants internal production of carbon. It utilizes this carbon to create and reinforce tissue as it grows, so it is a very valuable commodity. As we all know the plant also requires a form of nitrogen (N) and other macro and micro-nutrients which it receives through the root system. As already stated this N must be in a form which the plant can directly uptake and use, usually a form of ammonia (N). Research has shown that when a plant needs to uptake N from the soil it sends out some of its precious carbon through its root system as a feed for bacteria and *archaea which live in the rhizosphere. [* Archaea are prokaryotes indiscernible from bacteria except through specialized testing; usually DNA] There are more complexities involved, such as, that certain plant types attract certain bacteria/archaea types but that is beyond the scope of this portrayal. When the bacterial/archaea population has increased in response to the carbons excreted by the roots, protozoa and bacterial feeding nematodes are attracted to the region, hatch out from cysts and eggs respectively and in the case of protozoa multiply rapidly. Protozoa consist of flagellates, amoebae and ciliates. Some protozoa can multiply (divide) every 2 to 4 hours so their numbers can increase in short order. The protozoa and nematodes consume the bacteria/archaea and release, as waste, the ammonia (N) which the roots can then absorb. The multiplication rate of the bacteria/archaea increases in response to this predation and so on. This has been called the microbial loop. Protozoa are particularly good providers as their digestive system only utilizes about 30% of the nutrients consumed meaning that roughly 70% is released as the waste which the roots crave. This factor, combined with their short generational time makes them real feeding machines. Undoubtedly there are micronutrients also processed and absorbed in this cycle. There are still many mysteries which research has yet to unfold or are not yet known to this author.
This is not the end. The concert continues. The bacteria/archaea also consume the ammonia (N) which is now bioavailable to them, so are in competition with the plant for these nutrients. Because of this, if there are no predators or insufficient numbers to consume the bacteria/archaea they could potentially lock up the N. When the plant is growing it is in a vegetative state and requires a large load of available nitrogen (N) so it is advantageous for it to continue this release of carbon and maintain a balance of bacteria/archaea and protozoa, while uptaking just the right amounts of nutrients. Dont get me wrong. There are other players in this orchestra, either playing subdued roles or waiting their turn to play. There are higher order animals like mites, other microarthropods and worms. There are various forms of fungi, most of which are degraders but some of which are mycorrhizal. These all have roles in breaking down organic matter into a form which can then be mineralized by the plants bacteria/archaea team or delivered directly to the roots.
When the plant receives its signal from the upper world, above the soil, that it is time to switch gears and produce flowers and or fruit, its nutrient requirement changes. Although the mechanics are not well known to this author, studies indicate that the plant then increases the uptake of the ammonia (N) (bioavailable nitrogen) and reduces or stops excreting the carbon which feeds the bacteria/archaea. This effectively starves the bacteria/archaea which will react by dying or becoming dormant. This of course results in a similar reaction by the protozoa and bacterial feeding nematode population. The mycorrhizal fungi previously mentioned is then triggered into increased growth and production. Studies have indicated that the transference of bioavailable phosphorus and potassium to the roots occur mainly as a function of arbuscular mycorrhizal fungal hyphae in symbiotic relationship with the roots of the plant. The fungal hyphae (microscopic strands) grow right into the root cells and exchange nutrients. In exchange for carbon, once again released by the plant, the fungal hyphae delivers the required bioavailable nutrients to the root system. The fungal structure derives these nutrients from organic matter and food sources in the soil, some naturally processed by the other players as previously mentioned. It is my hypothesis that the form of carbon released to stimulate the mycorrhizal activity is of a varied molecular structure from that released to promote the bacteria/archaea population previously discussed, however I have no direct data to substantiate this. There are often different types of bacteria which accompany mycorrhizal fungi, adhering to the fungal hyphae in a symbiotic relationship. It is thought that these bacterial species function to exchange nutrients with the fungi as well as to protect the fungal hyphae from consumption by other microbes and even contribute to the protection of the plant from pathogenic fungi. There are other types of mycorrhizal fungi (ectomycorrhizal) which encapsulate roots rather than entering them but these are mostly associated with trees in the temperate and boreal regions.
So you see it is quite a complex arrangement which the plant conducts or controls and there are many facets which yet remain a mystery.
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** Addendum to Organic Growing From a Microbial Perspective
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Okay, since I wrote Organic Growing from a Microbial Perspective Ive received feedback which clearly outlines the need to explain the chemicals killing beneficial soil microbes thing, the role of NPK ratings as well as the pollutants statement. This feedback is justifiable. Please bear with the redundancy of the following. It reflects my attempt to be thorough.
It may be so, that some beneficial microbial life is out and out killed by chemical fertilizers but the more likely cause of death occurs over an extended period which Ill attempt to explain.
There are bacteria/archaea that will happily feed on chemical fertilizers. Indeed, there are bacteria that will 'feast' on diesel fuel. It is more likely that the use of chemical fertilizers negatively effect soil biota over a period of time. Chemical N (for example) is (to my knowledge) delivered to the roots of plants in ionic form, bypassing the whole microbial nutrient loop, which occurs through degraded organic matter being delivered in several processes; one major way being by bacterial/archaeal [sic] predation by protozoa (& bacterial feeding nematodes). It follows logically that if chemical fertilizers are used over an extended period (days? months? years?) that the microbial nutrient cycle will slow and/or cease.
The other side to this is that plants emit compounds from their roots which feed bacteria/archaea and fungi (of species conducive to their survival[?]) as an active participant in this microbial nutrient loop. Logically, if the plant is receiving direct feed ionic nutrients it is likely to slow and/or cease this process.
I compare this to a patient receiving intravenous feeding for a period of time and then needing to slowly adjust to real food again when the IV is discontinued.
The effects over a period of time (days? months? years?) will likely cause a die off of soil biota of a particular microbial consortia but may stimulate the growth of another microbial consortia (possibly/probably not as balanced and beneficial as the natural one), possibly causing disease.
I hypothesize another factor that may have effect is that when the plant is an active participant in the microbial nutrient cycle it 'decides' what nutrients it requires in time shifts unknown to us. If we are using chemical fertilizers quite likely much goes unused by the plant or is absorbed by the plant unnecessarily, perhaps promoting disease. The unused chemicals pass into the groundwater and streams or into the atmosphere. We've all heard the detriments around that and this is the pollution to which I refer.
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What about NPK in Natural Growing?[/SIZE]
Ill try to write something up which illustrates the difference between nutrient processing and utilization from a chemical and natural (or organic) standpoint (for want of a better word). The following information and opinion is stated by me and is derived from the citations and links provided. I use the words apparently and appears because I believe knowledge and science is fluid. I also dont pretend to understand everything perfectly and may need correcting. Just because we know the Earth is not flat does not mean we know everything about it.
To simplify things Ill restrict the discussion to the plants use of nitrogen (N). The forms of N which plant roots are able to uptake are in ionic form or soluble. These soluble forms of N are ammonium (NH4+) and nitrate (NO3-). Very simply stated these soluble forms of N are instantly available in chemical N and there is no need for any bacterial/archaeal (B/A) mineralization to make them available to the roots of plants. There is some indication that some soluble ammonium is utilized by B/A and mineralized into nitrates, however this appears (to me) somewhat an opportunistic occurrence (from the B/A perspective). So yes we can concur that B/A eats and thrives on some chemically provided ions but this action is not a necessary one for the plant to uptake exactly the same ions as are being consumed by the B/A. In certain circumstances the B/A will be in competition with the plant for these nutrients. So it appears that plants can grow in this fashion without interaction by mineralizing B/A. It appears that the chemically provided ions (soluble N) completely bypass the microbial nutrient cycle.
With natural or organic growing, N ( R-NH2 ) for the plant is contained (sequestered) in a non-soluble (non-ionic) form in organic matter (or in the case of the gardener; compost and other soil foods). It is true that there are certain known bacteria (and now some archaea) which directly fix and supply ionic forms of N to the roots of plants and this is an area where we are still learning so all is not known by any stretch. However soil scientists have discovered and it is common knowledge (as knowledge goes) that the bulk of NH4+ and NO3- are delivered to the roots of plants by protozoa (flagellates, amoebae and ciliates). This occurs in a complex network ostensibly, controlled in large degree by the plant. The plant releases compounds from the roots which feed B/A, thereby increasing the B/A population. The B/A consumes/processes forms of R-NH2 or forms which are pre-degraded by fungi and or other B/A. The B/A further multiply with a good supply of food and their large population encourages the excysting (hatching from cysts) and dividing of protozoa. The protozoa prey upon the B/A and in an approximate 30 minute period complete the excretion of NH4+ and/or NO3- available to the roots of the plants. Apparently protozoa only utilize 30 to 40 percent of the nutrient consumed making 60 to 70% available to plants and many have a division cycle of 2 hours so the efficiency of this nutrient delivery system is considerable. Just as it began, the microbial N cycle can be rapidly shut down by chemical emissions from the plant. It is apparent that the nutrient needs of the plant can change within short periods (perhaps in hours). There is much yet unknown, however I hypothesize that even disease control may be effected by a sudden reduction of N in the rhizosphere. This is certainly something which cannot be effectively manipulated by chemical N applications.
My goal in writing this was to illustrate the stark differences between the use by a plant of chemically provided ions and those derived through the microbial nutrient cycle. I believe I have succeeded. There are other ways which plants obtain N, such as through fungal interactions but that is nature; always have a back up.
I did fail to find information detailing the effects of chemical soluble N on protozoa populations. Although we humans have great confidence in our ability to mimic natural molecules sometimes we discover it is the subtle variances going unnoticed which end up having the greatest effects.
[SIZE=+1]Some References; [/SIZE]
Email me if you wish to track down these references.
[SIZE=-1]Protozoa and plant growth: 2003;
the microbial loop in soil revisited; Michael Bonkowski;
Rhizosphere Ecology Group, Institut für Zoologie, Technische Universität Darmstadt,
Darmstadt, Germany
Soil microbial loop and nutrient uptake by plants: a test
using a coupled C:N model of plantmicrobial interactions
Xavier Raynaud Jean-Christophe Lata
Paul W. Leadley
Plant Soil
DOI 10.1007/s11104-006-9003-9
The mycorrhiza helper bacteria revisited; 2007 P. Frey-Klett, J. Garbaye and M. Tarkka
Interactions Arbres/Micro-organismes, Champenoux, France;
UFZ-Department of Soil Ecology, Helmholz Centre for Environmental
Research, Halle, Germany
Modern Soil Microbiology; 2nd edition 2007 - Chapter 6 - Protozoa and Other Protista in Soil
Marianne Clarholm, Michael Bonkowski, and Bryan Griffiths
Soil protozoa: an under-researched microbial group gaining momentum
Marianne Clarholm
Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences (SLU), Box 7026, S-750 07 Uppsala, Sweden
Soil Biology & Biochemistry 37 (2005) 811817
SOIL BIOTA, SOIL SYSTEMS, AND PROCESSES
David C. Coleman
University of Georgia
I created a PDF from a write up I found on the WSU website. I created this without permission but I believe the authors won't mind. I think some may find it helps to clarify the NPK cycle, etc.
NPK Cycle
The link for the write up is
http://cru.cahe.wsu.edu/CEPublications/eb1722/eb1722.html
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[SIZE=+1]How to Apply All This to Horticultural Activities[/SIZE]
You say, okay so thats how it works but how do I apply that to my growing situation? The answer is pretty simple really. You need to assure that there is organic matter, mostly in the form of composted plant and animal (manure) substances in or on your soil for a microbial inoculant and food source. Additionally you can add microbial foodstocks such as diluted fish hydrolysate and molasses and kelp meal, alfalfa meal and rock phosphate and other clay and rock powders if available. It is very good to include rock phosphate in your composting process if you are making your own. Rock phosphate in the compost adds a long lasting source of phosphorus for microbes to draw from. At time of planting it is highly beneficial to place some mycorrhizal fungi spores in the hole or on the root system. You can research the best strain of fungi for the plants you are growing and purchase the spores from a number of suppliers. [
http://www.mycorrhizae.com http://www.fungi.com ] You may also consider seeding companion edible mushrooms which provide a dual benefit of cycling nutrients to your plants and providing your breakfast. You may research this at the fungi.com site. The rest is governed by the plant, as previously discussed, assuming that all the necessary components are available from the organic matter and additional foodstocks provided. In my opinion manipulation of the pH is not a wise practice in natural growing unless dramatic acidity or alkalinity are measured. Soil with a healthy microbial population tends to self regulate the pH. One should disturb the soil as little as possible so as to leave fungal growth and strands intact. I realize this is challenging when growing in containers. I have run trials where wooden bins were constructed (2x3x1.5 deep) where soil was successfully left intact after annual plants were harvested and replanted over several seasons. In between plantings composting worms were introduced to help consume the residual dead roots and plant matter. The worms were later trapped out. Compost tea was applied regularly to boost the soil microbial population. Over time there developed something of a miniature ecosystem complete with mushrooms, rove beetles and other beneficial bugs. If you are growing in smaller containers it is a good idea to provide a high volume of quality compost and or vermicompost at the onset.
Some people grow herbs and edible produce in containers organically. Because this has been practiced extensively utilizing chemical fertilizers, there is a period where growers have flushed the soil with copious amounts of water, the thought being that they are removing the harsh or harmful chemicals from the plant tissues. Too late! Those chemicals are already integrated into what you plan to put on your dinner plate or in your medicinal tea or pipe. At least thats my opinion. If you have grown your produce naturally allowing the plant to be in control, this flushing routine is not only unnecessary but sort of stupid. Since plants are not able to uptake organic nutrients, what exactly would you be flushing away? You might instead be water logging your soil and roots.
[SIZE=+1]Using Compost Tea[/SIZE]
The use of compost tea (CT) is one of the best ways to inoculate your soil with the beneficial microbes you wish to have for optimum health of your plants. It is also good if your supply of compost or vermicompost is limited, as it multiplies those microbes, we have been discussing, by the millions. Remember the protozoa I mentioned earlier? Well you can brew an aerated compost tea specifically to have a large population of protozoa, usually mostly flagellates. If you have a good quality compost or vermicompost, protozoa will already be present, often in a resting cyst. If you have an efficient aerated brewer you can pretty much count on having a high flagellate (protozoa) population combined with bacteria/archaea and fungal hyphae (not mycorrhizal) at 36 to 44 hours brew time (65 to 72 degrees F). If you have a microscope you can examine the CT periodically to be sure that the microbial population is optimum. The use of aerated compost tea also provides the opportunity to manipulate microbial populations for specific purposes by using various recipes and brew times. You may wish to have high bacterial or fungal numbers for pathogen/disease control or have soil or plants that require a higher population of a microbial type. I have a lot to learn yet of fungal species which can grow in compost tea so until I have learned to identify the species occurring Im cautious about some of the tricks employed to stimulate fungal hyphae growth in compost. Better to count on good quality compost and vermicompost with natural occurring quantities and species of fungi and use known mycorrhizal and mushroom spores in the soil.
As always, I am open to correction or refinement of what I have written.
Salutations,
Tim
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So You Wanna Build A Compost Tea Brewer[/SIZE]
Terms:
* = degree(s); CT = compost tea; ACT = aerated compost tea; O2 = oxygen; CO2 = carbon dioxide
DO2 = dissolved oxygen; CFM = cubic feet per minute; PPM = parts per million
There are several ways to make your own compost tea brewer which may not produce the equivalent results to some commercially available models but should provide you with a microbial extract you can apply to your soil and plants. When I first started messing around with brewers, I experimented with what we had lying in our various junk heaps around the farm; cast-offs from buying the wrong part at the plumbing store, outdated irrigation systems, left over pipe, dead vehicles and other modern broken things. Therefore, if you are a junk collector like me, you may already have much of what you require to build a compost tea brewer.
First of all Id like to make it clear that most aquarium air pumps dont produce enough air to use in a container larger than 1 gallon when considering making an aerated brewer. So dont even try the 5 gallon pail with the aquarium pump idea everybody is passing around. You need a minimum 0.05 CFM (cubic feet per minute), open flow of air and an optimum 0.08 CFM
per gallon (US) or higher to make aerated compost tea (ACT). ACT should have the DO2 sustained at or above 6 PPM. Generally, aquarium pumps produce around 0.02 to 0.16 CFM. Another generality is that 25 watts of power usually produces 0.75 to 1.0 CFM in diaphragm air pumps. The wattage is usually marked on the pump which will help you figure out the approximate output. Ill cover more on air pumps later.
In the following I will outline some simple methods of building a variety of compost tea makers. I am not going to discuss anaerobic methods at this time. Later on I may add some sketches.
1/ [SIZE=+1]Stir Method:[/SIZE] The cheapest way to make compost tea is the old fashioned way. Just add compost to clean, non-chlorinated, water (above 65 degrees F. recommended) and stir like mad with a clean stick or whathaveyou. Id recommend using about 3 to 5% compost by volume of water and stir it up as often as you can over an 8 to 12 hour period. Some people do it over a 24 hour period and also add some foodstock like molasses, fish hydrolysate and kelp. You can experiment with different times and ingredients and decide for yourself. If you have a microscope, check it out. When you feel that you have a completed compost tea (CT) you can remove it in several ways. If you have just used a 5 gallon pail you can simply let the particulate matter settle and pour the clearer CT off into watering cans or your sprayer.
[SIZE=+1]Filtering;[/SIZE]
You can place a submersible pump into a mesh bag as a screen, drop it into the tank (barrel, pail) and pump the CT out. I use a regular cheap sump pump for this with a 800 to 1000 micron mesh bag (about the size of window screen) See the testing I did; [/SIZE]
Does Microbial Life Survive Pump Impellers?[SIZE=-1] . You can purchase mesh bags at
www.aquaticeco.com or make your own. Likewise, you can filter the CT by placing the same size screen over top of another pail and pour or siphon the CT through the mesh into the other vessel. If residue builds up, stop and clean off the mesh. As residue builds up it stops the passage of the microbes you want. Never run CT through a pipe constrained filter unless essential as part of your irrigation system or spray rig.
2/[SIZE=+1] The Venturi Method:[/SIZE] If you only have a water pump and wish to make a compost tea brewer you can inject air into the water by using a venturi. I have provided a
sketch and
text showing how to make your own or you can purchase them from
http://www.aquaticeco.com . Basically the venturi creates a vacuum which interfaces with the water as it passes by, sucking air and mixing it with the water. It is quite an efficient method of oxygenating water. If you have a really tough water pump which does not clog, like a trash pump, you may run this type of brewer without a mesh extractor bag. Most are going to want to use a mesh extractor, so I recommend TEEing your water line downstream from the venturi with one return line suspended above the water and the other return line going into the mesh extractor. Undoubtedly you will require a valve to regulate the flow so all of the water does not just take the easiest route to the pipe suspended over the water. To build a CT brewer beyond the stir method, some basic knowledge of fitting plumbing parts and pipes together is essential, as well as some engineering instincts. If you are not up for this just save yourself the aggravation and buy a brewer. You may use your imagination for a mesh extractor. For a small brewer of 100 gallons or less, 400 microns is an ideal mesh size. Sometimes for large brewers which may run for several days to establish a functional nutrient cycling consortia a larger mesh size like 800 µm may be a better choice. This is because, as noted above, the mesh may clog up a little over time. A friend of mine successfully brewed CT using this method in a 5000 gallon brewer for many years. He used 2, barrel sized mesh extractor bags sewn from landscape cloth. He ran a return line into each bag, which was ¾ full of compost and tied off each bag tightly around the pipe so nothing could get out the top. These were dropped into the water (with his tractor) and 2 other return pipes pumped in oxygenated water. You can use your imagination to create mesh extractors, dependent on the size of your brewer, the materials at hand and what works for you. You can even create a basket which is partially above the surface to prevent particulate escape. These systems are not great for extracting and growing fungal hyphae but they produce bacteria/archaea and protozoa just fine.
[SIZE=+1]The Gas Exchange;[/SIZE]
The reason for suspending the other pipe(s) above the water is so it splashes into the water, breaking the waters surface tension and additionally pushing more air into the water like a water fall or running river does. The surface tension of water is unique in its toughness; it surpasses that of oil. When I first started experimenting with the venturi method I had the return pipe submerged. The effects were profound. As the water filled with air, generated by the venturi, the water level rose, even over flowing my 1200 gallon tank. At the time, I thought this was a good sign that I was oxygenating the water. Sure, I was getting air in but was not getting the maximum dissolved oxygen possible with my system. Later when I learned that gas exchange means, trading one gas for another, I realized that the surface tension must be broken for the optimum gas exchange to occur. In this case, we are trading carbon dioxide (CO2) for oxygen (O2) or dissolved oxygen (DO2). CO2 must make way for DO2. In water, CO2 has two ways of being dissipated (of which I am aware). It is either used by organisms, like water plants or it must escape at the surface interface. In a brewer we have no plants and the microbes we are growing use O2 and create CO2, so the CO2 must escape at the surface. Because of the high surface tension of water, if we break the surface, this escape or release is facilitated and we improve the efficiency of our CT brewer. Once we started suspending the return pipe above the surface, providing a hardy splash to break the surface, we had no further over flows and the DO2 increased.
NOTE: This principle applies to air driven brewers as well. The better the surface tension is broken, the better the capacity to contain DO2 in the water.
3/ [SIZE=+1]The Vortex Method: [/SIZE]There are many who claim that running water in a vortex pattern comprised of multiple mini vortices changes the properties of water beneficially. I remain dubious but open-minded. You can form your own opinion on this subject. One thing a vortex brewer is very good for is ensuring a full circulation of all the water and compost added. There can be no dead zones; none of the feared anaerobic pockets!! There is no point to considering the use of a mesh extractor with a vortex brewer unless you conceive of some genius method of suspending a mesh container in the center of the flow. Therefore this design is for those of you who dont mind using compost in free suspension and deal with the particulate matter later. A vortex action in a CT brewer is pretty much dependent on the shape of the vessel used, combined with the direction of the input flow nozzles or pipe ends and finally on the ability of the design to empty from a centrally located opening at the bottom of the vessel and the return of the water emptied, to the top of the vessel, to repeat the trip. Shapewise, you must use a round configured vessel. The most efficient shape is a cone shape with a drain hole at the bottom. Rather than go through a complex description of how to construct an air driven vortex brewer, Im including this Internet link which illustrates a design by Steven Storch which he has offered up to the public;
http://www.subtleenergies.com/ormus/tw/turbo-vortex.htm One with engineering instincts will come up with a variety of ways to modify this design. For example this design can be transposed to a 50 gallon sized barrel with a drain hole placed in the bottom. You would of course need a larger air pump and need to set the barrel up on blocks or legs. These systems produce a full compliment of microbes (bacteria/archaea, protozoa and fungal hyphae).
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One can also create a vortex brewer using a water pump to return the water to the top of the vessel again. Very handy if that is what you have laying around in your junk pile. The advanced thinkers will have already mindfully jumped to the idea that including a venturi with a water pump driven vortex is going to increase its efficiency exponentially. Well
.at least a lot. Give yourself a gold star, a pat on the back, a chocolate cookie. Bear in mind, that if you use a water pump you will limit fungal hyphae extraction and growth.
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3a/[SIZE=-1][SIZE=+1]
Simple Airlift - Vortex: [/SIZE][SIZE=+1]done my way[/SIZE]
I've had many requests to provide a simple design for an airlift brewer. This
sketch of a simple design cone bottom tank brewer can be applied to just about any size brewer. Just don't start selling them or I'll have to sue you.
If you wish to create a vortex using this design make sure you use a round shaped tank and position the return nozzle (elbow) so it is directional to the flow desired. This can be reversed by twisting the elbow and tweaked by using a short length of pipe as an extension. I'll try to post some photos shortly.
4/ [SIZE=+1]Bubble Blowers;[/SIZE] There are 2 basic styles of commercial bubble blower CT brewers. What I mean by bubble blowers, is that their function depends on just that; blowing bubbles into the water, into a mesh extractor or both. They do not actively move the water, aside from the effect of the bubbles. Because of this, I find it a paradox that they refer to their units as AACT (actively aerated compost tea) brewers to separate themselves from only, aerated compost tea (ACT) brewers, which supposedly just blow air into water. This remains a mystery unto me. I wont name these brewers because they include almost every commercial brewer available, except mine of course, which should be separated from those by being called an AAACT brewer (giggle). No offense; just kidding around.
Anyway, back to business. A very simple method you can use to make an aerated CT brewer is to use some rigid PVC thin walled pipe (not schedule 40 because it is difficult to make tiny holes in) of approximately ½ inch to ¾ inch size. Rigid pipe is better than flex pipe because it holds its shape, can be cleaned more easily and is easier to drill and saw. Use a straight piece which is approximately as long as your proposed tank is high, joined to a 90* elbow, then following the dimensional circumference of the bottom of your tank build a roughly round hexagon or octagon or whateveragon alternating with PVC fittings (45* or 11*, 22* to 30* if you can find them
http://pvcfittings.com ) and short lengths of pipe, terminating just before you hit the elbow which the long pipe slides into. Over the end of this last piece of pipe in your whateveragon slide a cap. None of this needs to be glued (usually) because we are not dealing with high pressure and the whole thing can be taken apart for easy cleaning. We now need three more things. An air supply, an air input interface with the pipe and diffusers. A diffuser is an interface between air and water which diffuses of course, air into the water. No matter what name people give it, like orifice or air stone, hole, slit or slot, it is still a diffuser. The smaller the diffuser opening within the capacity of the air pump to push air through easily, the greater the efficiency at raising and maintaining the dissolved oxygen. Therefore you want to put the smallest holes or slits possible at intervals in the short pieces of pipe you used to construct your whateveragon. If you have an electric drill you can drill 1/16th inch holes. You can try cutting slits with a razor knife or very fine hack saw or other blade. A hacksaw cuts around 1000 microns width. I get machined slots which are 254 microns. Make your openings so they are coming out the bottom angled towards the center to begin with. (The pipe is not glued so you can rotate them). For your first trial only put a few air openings in each length of pipe (e.g. 2 spaces). We want the air traveling all the way to the end of the whateveragon. Now to try it out, I guess we better get some air happening.
First of all, for your air input you need to match air tubing with your air pump and get a threaded barbed fitting that the tubing fits over and a slip X female threaded coupling to go over your long straight piece of PVC pipe which goes down and joins to your whateveragon. This, you may need to glue.
I have provided a rudimentary representative sketch to help illustrate the basic construction >
click here
[SIZE=+1]A Word About Diaphragm Air Pumps;[/SIZE]
If you are going to buy a pump to run your aerated CT brewer, I can recommend the Eco Plus Commercial 5 (4 CFM max.) for up to 50 gallons and the Eco Plus Commercial 1 (1.75 CFM max.) for up to 10 gallons. Im sorry but I cannot recommend a retailer for these pumps. I buy them wholesale and perhaps if you contact them, they can refer you to a retailer.
http://www.nationalgardenwholesale.com
I can also recommend Hailea 9730 pumps (2 CFM max.) which you can purchase from
www.aquaticeco.com and other places. These are solid, long lasting pumps and I know other commercial brewers use them for 50 gallons but I just cant recommend them for more than 30 gallons. If you use one for a 5 gallon unit it will last virtually forever. All of these pumps come with a little threaded brass fitting for screwing into the air output.
DO NOT USE THESE! Put them in your parts drawer. These constrict the air and reduce your CFM by at least 20%. Rather, find tubing which slides over the nipple into which the threads are tapped. In the case of the Eco Plus 5 and the Hailea, 5/8ths inside diameter works. Slide the air tubing over and secure with a gear clamp. The Eco Plus has a very short nipple so I score the metal with a couple of swipes with a hacksaw to create barbs for the tubing to grip. You can find tubing at a building supply like Home Depot or Rona in Canada. I use the braided reinforced stuff which does not kink. Always try to keep your pump at or above the surface of the water so it does not siphon back if the power fails.
Now that we have our air supply you can slide the tubing over the barbed fitting air input on the end of your straight piece of PVC and fire her up. Ooops! Forgot the spring clamp. You can use a spring clamp to pinch the long PVC air pipe to the edge of your tank at the top. This keeps the hole thing from floating and you can adjust the distance your whateveragon is from the bottom. Spring clamps are like giant clothes pegs
http://www.leevalley.com/wood/page.aspx?c=1&cat=1,43838&p=41712
http://www.hobbytool.com/springclamps.aspx
Im sure you can find them at Home Depot too or you may think up another idea (like a C clamp).
Okay fire up the pump and fill up your tank (pail, barrel) with water. Watch the amount of air coming out of the openings you made. What we want is air coming out right to the end of the whateveragon and even dispersal all around and we want really broiling water bubbling up to the surface. The reason I suggested angling the openings on the bottom towards the center of the tank is so it would sweep right up from the base. You can raise it closer to the surface to get a better look at how evenly the air is coming out. You can also just put the air tube end in the water, right to the bottom so you can get an idea of your air potential and how much should be coming out of the holes you made. You dont want to restrict the air flow. If you feel comfortable that you need more air coming out start adding more openings (on top), beginning at the cap end on the top of the pipe and working your way around towards the air input. Youll get the hang of it. If you screw up, no biggy cause you are using really short pieces of very cheap pipe, not glued and you can redo and experiment to your hearts content.
This is very similar to the KIS 5 gallon brewer (a very efficient little brewer; buy one if you don't like doing this) so their compost brew kits will be ideal to use with this. You can use this system with compost and feedstock in free suspension (added directly to the water) or in the case of a 5 gallon set up you can probably get away with placing your compost and solid food into a mesh bag tightly tied up and floating around in the water. The turbulence may keep it suspended. You could put some fishing floats or ping pong balls in it to be sure it wont sink.
If you wish to use an extractor bag with a larger brewer, then you can use a variation of the set up previously described, except that you have a PVC air line entering your (tube/sock shaped) mesh extractor bag with diffuser openings close to the bottom of the bag and with a cap on the end of the pipe. This pipe should go very close to the bottom of the bag. You will need to tie off or fashion a lid for the extractor bag or keep the top above the water surface. As stated previously, 400 microns is the optimum sized mesh to use. You may purchase a variety of mesh bags from
http://www.aquaticeco.com . You can experiment with the number of diffuser openings which provides sufficient agitation. These types of systems depend upon the agitation of the compost against the mesh, caused by the air, to extract the microbes from the compost. Some systems have no additional air diffusion outside of the mesh extractor, while others incorporate one or more additional diffusers. One could TEE off from the air line, one diffuser going into the mesh bag, the other into the water. A valve to regulate the air flow would be necessary in this case. Alternatively one could use two air pumps. One could combine both designs, using a whateveragon diffuser and another pipe going into the mesh extractor.
[SIZE=+1]Diffusers;[/SIZE]
One could incorporate good quality glass bonded diffusers if one did not wish to mess with PVC pipes and making their own diffusers. These diffusers are resistant to break down by microbes and can be cleaned with muriatic acid (but are not environmentally friendly to clean). They are called Sweetwater medium bore diffusers and are available at
http://www.aquaticeco.com . They are far superior to homemade PVC diffusers in terms of sustaining DO2 because they produce finer bubbles . There is no truth (that I have seen) to the statement that fine bubbles damage some microbes.
[SIZE=+1]Anaerobes;[/SIZE]
Many people are overly anxious about having any anaerobic microbes in their CT. If you have a tremendous number of ciliates in your CT, or if it stinks to high heavens, there is a likelihood that your CT has gone anaerobic and you should toss it. However, I would not worry about seeing a healthy number of ciliates (if you have a microscope), especially if there are also high numbers of flagellates and/or amoebae. Additionally anaerobic (facultative and obligate) bacteria and archaea occur naturally in the soil and other environments and their existence is part of the balance of nature so dont worry if you have a few in your consortia.
[SIZE=+1]Cleaning;[/SIZE]
You should clean out your brewer after each use, especially the extractor bag if you use one.
[SIZE=+1]Conversions;[/SIZE]
1 US gallon = 3.78 litres (liters)
1 US quart = 0.946 litre (liter)
1 micrometer or micron (µm) = 0.000039 inch (39/100000ths)
For converting mesh to microns:
http://chemplazaonline.com/meshsizecoverter.aspx
I think Ive covered the basics. If anyone has any suggestions or if you notice any errors, please speak up.
[/SIZE]
[SIZE=+2]
Some Photo, Video and Linked Resources for Organism Identification:[/SIZE]
Vorticella (<5 MB) This is little video of a Vorticella ciliate
Here is
Part 1 and
Part 2 PDFs of some photos and notes I put together to assist folks with idendifying soil, compost and compost tea microbes. Please use these PDFs freely for educational purposes. Part 1 includes bacteria, flagellates, amoebae, ciliates and fungal hyphae. Part 2 covers nematodes and rotifers.
Here are links (which I hope remain current) to Internet resources which will assist in microbial identification.
Mastigophora - Flagellates
http://protist.i.hosei.ac.jp/PDB/Images/Protista/MastigophoraE.html
Ciliophora - Ciliates
http://protist.i.hosei.ac.jp/PDB/Images/Protis
Sarcodina (Sarcodia) - Amoebae
http://protist.i.hosei.ac.jp/PDB/Images/Protista/SarcodiaE.html
http://now.ifmo.ru/amecol/frames.htm
http://amoeba.ifmo.ru/guide.htm
You can find good images of testate amoebae by googling Edward Mitchell + testate amoebae
Fungi Images & Info
http://www.uoguelph.ca/~gbarron/index.htm
http://www.mycolog.com/index.html
Actinobacteria (mycetes)
Digital Atlas of Actinomycetes [now referred to as Actinobacteria]
http://www.nih.go.jp/saj/DigitalAtlas
Lots of cool organisms by Wim
http://www.microscopy-uk.org.uk/mag/indexmag.html?[url]http://www.microscopy-uk.org.uk/mag/wimsmall/smal1.html [/URL]
[SIZE=+1]
Please inform me of any dead links.[/SIZE]
Even worse than not seeing cops, she things they're actually here to just protect and serve 
Its not in an area where we spend a lot of time, so I'm not too concerned with the health risks. When it burned out I also ordered the fresh linen ona! Its not here yet, I'm hoping for tomorrow.
Stay cool homies, ttyl.
