Abstract:
The present invention relates to an extraction and brewing machine having a tank, a fan assembly, a base aerator, an extractor head, and an extraction assembly. The extraction assembly has a container for being submerged in liquid held within the tank, and an extraction aerator. The container is comprised of a dome and a filter. The dome defines an interior region for vigorous mixing of air, compost and water. The filter can be a mesh bag. The extraction aerator can have openings near the bottom of the bag. The flow of air though the filter causes a current of liquid, air and microorganisms to exit the chamber. The base aerator aerates all the liquid in the tank. The microorganisms in the tea continue to grow and multiply in the tank after extraction from the chamber, and no particles pass the filter that could jam a spray nozzle.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an extraction and brewing machine, and more particularly to a machine having an aeration container where particles or microorganisms can be extracted through a filter into a larger aeration tank. 
     2. Description of the Related Art 
     The use of fertilizers is well understood to aid in the growth of plants. Chemical fertilizers in particular are extensively used today. Chemical fertilizers are used residentially in applications such as residential lawns, flower gardens and vegetable gardens. Examples of commercial use of chemical fertilizers include golf courses and farms. While chemical fertilizers may work well for their intended purposes, there are some drawbacks associated with their applications. Overuse of chemical fertilizers can be harmful to exposed areas, as evidenced by patches of “burnt” lawns. Further, children and pets should stay clear of treated areas until after the chemical fertilizer has been worked into the soil. This commonly occurs during a rainfall. Runoff of excess chemical fertilizers can further cause damage the overall ecosystem. 
     Organic compost has long been known to be an excellent fertilizer and soil conditioner. When properly tended to, compost comprises many beneficial microbial organisms, or microorganisms. Among the many beneficial microorganisms are bacteria, fungi, protozoa and nematodes. Benefits of using organic compost include aiding in the natural biological process in soil to make nutrients and water available to root systems of plants. Further, the microorganisms in the organic compost can help protect plants from disease causing organisms, improve nutrient retention and water retention of the soil, reduce or eliminate harmful pesticides, and decompose harmful toxins. Use of organic compost to cover widespread areas is impractical, as the amount of area that can be treated with the compost is limited based on the amount of compost. The economics of obtaining and spreading large quantities of compost effectively further limits its practicality. 
     Many attempts have been made to extract and/or grow the beneficial microorganisms found in the compost. The process generally comprises the steps of extracting beneficial microorganisms from compost and/or aerobically growing the microorganisms in water or other liquid. A solution made of water and microorganisms is called compost tea, or simply tea. The process of growing the tea is called tea brewing. The tea can be applied to the soil in place of and/or in addition to chemical fertilizers. A goal of applying microorganisms to the soil is to enhance the soil, not necessarily to replace the need for chemical fertilizers. In this regard, the microorganisms are useful in making the chemical nutrients available to the plants. One common method of application of the tea utilizes spray nozzles to mist the tea over a selected area. Compost having certain characteristics and quantities of organisms can be used to brew tea with specific characteristics or quantities of specified microorganisms. A benefit of using tea is that the beneficial microorganisms can be applied to a large area. Another benefit of using compost tea is that the tea is not harmful to children and pets, and that use of the treated area can resume quickly without waiting for a rainfall. 
     Some extraction machines utilize mechanical mixers used to mix the compost in water. While the mechanical mixers are efficient at mixing the compost and water, the mixers also can harm or destroy the microorganisms in the compost. Further, the more vigorous the mixing, the greater the potential damage to the microorganisms. Still further, in a non-aerated mechanically mixed environment, the oxygen demands of the microorganisms can quickly deplete the available dissolved oxygen in the liquid. Non-beneficial or harmful microorganisms could then proliferate under the anaerobic conditions. 
     Sometimes the compost is mixed with the tea in a single large aeration tank. In such a situation, the tea must be strained or filtered before use to prevent the tea from jamming the nozzles of a sprayer machine. One drawback of filtering the tea after it is brewed is that filtering the tea may filter out many or most of the beneficial microorganisms. 
     A system exists comprising an aerated tank with a filter supported within the tank. One such system is sold under the name Bobolator. In this system, the microorganisms that escape through the filter can grow in the tea. However, the filter used in this system is partially open directly to the atmosphere. A large percent of the air exiting the filter therefore passes directly to the atmosphere without first passing through the filter into the larger tank. The air that passes directly to the atmosphere does little to aid in the extraction of microorganisms through the filter. Accordingly, only a limited quantity of microorganisms passes through the filter and into the tank. 
     Other systems have been designed having a bag filled with compost that is submergible in a tank. One such system is sold under the name Simplici-tea. In this system, the bag is free to move anywhere in the tank. Further, there is no active process for specifically aerating the bag or drawing air through the bag. Therefore a limited amount of the air may pass through the bag, and the extraction rate can be less than optimal. 
     Many systems use plastic components, which can be easily scratched. It is difficult to clean scratched plastic components, and microorganisms can remain in the scratches. Anaerobic conditions can develop in the scratches, and non-beneficial or harmful microorganisms can proliferate under anaerobic conditions. 
     Thus there exists a need for an improved tea extractor and brewer that solves these and other problems. 
     SUMMARY OF THE INVENTION 
     Organic fertilizer and compost tea have many desirable attributes, especially when compared to chemical fertilizers and used in addition to chemical fertilizers. A high yield tea brewing machine is therefore desirable. The present invention relates to an extraction and brewing machine having a tank, a fan assembly, a base aerator, an extractor head, and an extraction assembly. The extraction assembly can have a container for being submerged in liquid held within the tank. The container can be comprised of a dome and a filter. The dome can define a jostling chamber comprised of the interior region of the dome bound by top and side wall. The filter can be a mesh bag depending from the dome and having openings of a predetermined size. The extraction assembly can further have an extraction aerator with openings near the bottom of the bag. During use, the compost can be vigorously jostled in the interior region of the dome. The base aerator is useful to aerate the liquid in the tank. 
     According to one aspect of the present invention, the tea brewer is 100% air driven. That is, air is used to jostle the compost and extract the microorganisms from the compost. Also, the base aerator is useful to aerate and mix the liquid, or brew, in the tank. One benefit of the present design is that highly aerobic conditions are provided in the tank for promoting the growth of beneficial microorganisms. Another benefit is that air jostling vigorously mixes the compost without harming the microorganisms. 
     According to another aspect of the present invention, the compost is vigorously jostled in a submerged container. The volume of air entering the container though the extraction aerator generally equals the volume of air exiting the container through the filter. The microorganisms in the compost are generally smaller than the holes in the filter. The flow of air though the filter causes a current of liquid, air and microorganisms to develop in a manner exiting the container. The rate of microorganism extraction is greatly improved by producing a flow, or current, of air, liquid, and microorganisms exiting the container. Water is able to flow into the container near the bottom to replace the water leaving the filter with the air. 
     According to a further aspect of the present invention, the container contains a region defined by the dome where vigorous jostling can take place. The dome is initially filled with air as it is submerged in the tank. Air entering the container has a tendency to raise straight up when released in the bottom of the container. The rising air in the container can enter the dome, where it can vigorously mix with compost, liquid and other air. The vigorous jostling creates a preferred environment where microorganisms can separate from the remainder of the compost. Improved separation of the microorganisms from the remainder of the compost increases the number of microorganisms that are available to be extracted from the container. 
     According to yet a further aspect of the present invention, the tea that is grown in the tank contains no particles that could jam common-sized spray nozzles. That is, the relatively large compost particles that could otherwise jam a common-sized spray nozzle remain in the container and are not able to pass through the filter. 
     According to a still further aspect of the present invention, the components can be made from hardened materials, such as stainless steel. The hardened materials are resistant to scratching and easy to clean. Clean and scratch-free surfaces do not provide conditions favorable to anaerobic growth of non-beneficial microorganisms. 
     According to a still further aspect of the present invention, the components are collapsible for shipping. The fan assembly, base aerator, extractor head, and extraction assembly can fit within the frame for shipping within a box. 
     Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred embodiment of the present invention. 
         FIG. 2  is a top view of the preferred embodiment shown in  FIG. 1 . 
         FIG. 3  is a side view of a preferred embodiment of the extraction assembly of the present invention. 
         FIG. 4A  is a sectional view taken along line  4 - 4  in  FIG. 3 . 
         FIG. 4B  is a close up view of the band clamp securing the filter to the dome above the lip of the dome. 
         FIG. 5  is a sectional view taken along line  5 - 5  in  FIG. 2 . 
         FIG. 6  is a close-up view of a section of the base aerator shown in  FIG. 1 . 
         FIG. 7  is a close up view of the bottom end of the extraction aerator in the extraction assembly shown in  FIG. 1 . 
         FIG. 8A  is a sectional view of the extraction assembly showing a selected amount of compost in the extraction assembly. 
         FIG. 8B  is a schematic view of an embodiment of the present invention showing operation of the preferred embodiment. 
         FIG. 9  is a perspective view of an alternative preferred embodiment of the present invention. 
         FIG. 10  is a perspective view of an alternative preferred embodiment of the present invention. 
         FIG. 11  is a top view of the alternative preferred embodiment shown in  FIG. 10 . 
         FIG. 12  is a sectional side view of the alternative preferred embodiment shown in  FIG. 10  taken along line  12 - 12 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
     The present invention utilizes a liquid  1  as a medium for allowing microorganisms to grow. One preferred liquid  1  is water. However, other liquids could alternatively be used without departing from the broad aspects of the present invention. Gas  2  containing oxygen is aerated through the liquid  1 , as described below. It has been found that atmospheric air contains sufficient oxygen to adequately aerate the liquid  1 . However, other gaseous mixtures including oxygen can be used without departing from the broad aspects of the present invention. Compost  3  containing large particles  4  and smaller particles such as microbes, or microorganisms  5 , is a preferred substance from which microorganisms  5  can be extracted. It is well understood how to make quality compost. 
     According to one preferred embodiment of the present invention, an extraction and aeration apparatus  10  is provided. The apparatus  10  has a tank  15 , a frame  30 , a fan assembly  35 , a base aerator  50 , an extractor head  55 , and an extraction assembly  60 . These components are described in detail below. 
     The tank  15 , as best shown in  FIGS. 1 ,  2  and  5 , has a first side (front)  16  and an opposed second side (rear)  17 , and has sides  18  and  19  between the front  16  and rear  17 . The tank  15  also has a top  20  and a bottom  21 . The sides  16 ,  17 ,  18  and  19 , and the top  20  and bottom  21  preferably define a generally box shaped tank, with interior dimensions approximately 40 inches wide, by 46 inches deep, by 42 inches tall. However, it is understood that the shape and particular dimensions of the tank  15  can vary without departing from the broad aspects of the present invention. It is preferable that the intersections of the side walls and the top and bottom, respectively, are radiused to eliminate havens where harmful microorganisms can flourish. The tank  15  can be made of plastic material, metal, or any other material suitable for non-pressurized tanks. In the preferred embodiment, an exit orifice  22  is located on the front  16  of the tank  15  near the bottom  21 . The orifice  22  is used to drain the contents of the tank  15 , and accordingly has a valve used to selectively open and close the orifice. Optionally, the tank can be framed with a metal cage  23 , and can have a pallet-type base  24  enabling the tank  15  to be moved with a forklift. The metal cage  23  and base  24  are shown in  FIG. 9 . The preferred dimensions of tank  15  are sufficient to accommodate approximately 250 gallons of liquid  1 . A tank with this volume has been found suitable for operation and transport in the bed of a full sized pickup truck. 
     The frame  30 , shown in  FIGS. 1 and 2 , can be located on the top  20  of the tank  15 . The frame  30  can preferably be made of stainless steel. The frame  30  preferably has a length equal to the width of the tank  15 . In the illustrated embodiment, the frame  30  is offset from the rear  17  of the tank. 
     The fan assembly  35  is preferably housed within the frame  30 . As seen in  FIGS. 1 and 2 , the fan assembly  35  preferably has a fan  36 , or blower, and an air filter  37 . The fan  36  is preferably capable of moving 30 cubic feet per minute, or cfm. A tube  38  is connected to the fan  36 . The tube  38  splits to two tubes  39  and  41 . Tube  39  can be selectively opened and closed with valve  40 . Tube  41  can be selectively opened and closed with valve  42 . The tubes  39  and  41  are preferably made of steel. However, rigid plastic tubes could also be used without departing from the broad aspects of the present invention. Tubes  38 ,  39 , and  41  preferably have a diameter of approximately 1.5 inches. While the tubes  38 ,  39  and  41  are shown to be generally circular in shape, it is understood that the tubes could also be other shapes, such as square. 
     The base aerator  50 , as shown in  FIG. 5 , has a depth tube  51  and a lateral base tube  52 . The depth tube  51  is preferably substantially vertical, and has a preferred diameter of approximately 1.5 inches, and is preferably located near the side  18  of the tank  15 . The depth tube  51  can be made disconnectable to allow for shipping and storage. The tube is preferably located equidistant between the front  16  and rear  17  of the tank  15 . The lateral base tube  52  is preferably substantially horizontal and located near the bottom  21  of the tank  15  near side  18 . The base tube  52  preferably has ends that are located equidistant from lateral tube  51 . Base tube  52  preferably has a diameter of approximately 1.5 inches. Several openings  53  are located through the base tube  52  to allow the air to escape into the tank  15 . The openings  53  are preferably located through the bottom of the tube  52 , but can be located elsewhere around the tube without departing from the broad aspects of the present invention. A close-up cross-sectional view of a section of the preferred base aerator is shown in  FIG. 6 . While the base tube  52  is shown to have a generally circular shape, it is understood that is can also have other shapes. It this preferred embodiment, the base aerator  50  is integral with tube  39 . Base aerator  50  preferably has an aeration rate of approximately 22 cfm. It is understood that the base aerator  50  could have a larger or smaller aeration rate without departing from the broad aspects of the present invention. 
     The extractor head  55  is preferably integral with tube  41 . The extractor head  55 , as shown in  FIGS. 1 and 5 , preferably comprises a generally vertical tube  56 . Tube  56  has a top and a bottom. The bottom of the tube  56  preferably has a yoke  57  for removeably connecting to another tube (discussed below). The extractor head  55  preferably has a diameter of approximately 1.5 inches. It is understood that the extractor head  55  could have a different size and shape without departing from the broad aspects of the present invention. 
     The extraction assembly  60 , as is shown in  FIGS. 3-5 , defines a container  61 . The container  61  has a top portion and a bottom portion. In a preferred embodiment, the container  61  has a volume of four to five gallons. However, the container  61  could be larger or smaller without departing from the broad aspects of the present invention. The container  61  is sized to hold a selected amount of compost  3  or other material. The extraction assembly  60  is removeably connected to the extractor head  55 . In this regard, the extraction head  55  holds the extraction assembly  60  in an intended location within the tank  15 . The extraction assembly  60  generally comprises an extraction aerator  65 , a dome  70  and a filter  80 , each of which are described in detail below. 
     The extraction aerator  65  has a top  66  and a bottom  67 . Openings  68  are located near the bottom  67  for allowing air to exit the extraction aerator  65  during use. The extraction aerator  65  is preferably a straight and tubular shaped and has a diameter of approximately 1.5 inches. However, it is understood that the extraction aerator could have other shapes or sizes. The extraction aerator  65  is preferably rigid, and is preferably made of stainless steel. The top  66  of the extraction aerator  65  removeably connects to yoke  57  of the extractor head  55 . An end cap  69  is preferably at the bottom  67  of the extraction aerator  65 . The end cap  69  can be removed from the bottom  67  to allow for cleaning of the extraction aerator  65 . A close up view of the bottom  67  of the extraction aerator  65  showing the openings  68  and end cap  69  is shown in  FIG. 7 . Extractor aerator  65  preferably has an aeration rate of approximately 8 cfm. However, it is understood that the aeration rate could be greater or smaller without departing from the broad aspects of the present invention. 
     The dome  70  has a top  71  and a sidewall  72 . The sidewall  72  has a top and a bottom. The top  71  and sidewall  72  have an interior surface and an exterior surface. A lip  73 , as best shown in  FIG. 4B , preferably surrounds the sidewall  72  at the bottom exterior surface of the sidewall. The interior of the dome  70  defines an interior region  74 , or simply region. A handle  75  can optionally be connected to the outside surface of the dome. The dome is preferably made of stainless steel. In the illustrated embodiment, the extraction aerator  65  passes through the center of the dome  60 . It is understood that the extraction aerator  65  could extend around the outside of the dome without departing from the broad aspects of the present invention. While the dome shape has been found to be a preferred shape, other shapes are possible. 
     A preferred filter  80  is a mesh bag  81 . The mesh bag  81  has openings  82  preferably sized approximately 400 microns. However, the openings  82  could be between about 250 and 841 microns (20 to 60 mesh) without departing from the broad aspects of the present invention. The mesh bag  81  further has a top  83  and a bottom  84 , an interior surface and an exterior surface. The bag  81  preferably has an interior capacity of approximately 4 gallons. A clamp  85  is preferably located at the top  83  of the bag  81 . The clamp  85  can be a band clamp, and it is used to removeably secure the bag  81  to the dome  70  by tightening onto the exterior surface of the dome  70  above the lip  73 . It is shown in  FIGS. 3 and 4A  that the extraction aerator  65  extends to near the bottom  84  of the bag  80 , and passes through the interior of the bag. Alternatively, a rigid filter such as a wire mesh cage could be used without departing from the broad aspects of the present invention. Further alternatively, the extraction aerator could pass around the exterior of the filter  80  and have an opening at the bottom  84  of the filter. The filter  80  can be a single-use filter or a reusable filter. 
     Turning now to the operation of the present invention, the aeration apparatus  10  can be unpacked and assembled. In this regard, the components  35 ,  50 ,  55 , and  60  can be contained within the frame  30  while being shipped. The frame  30  can be set on top of the tank  15 . A selected amount of water (preferably approximately 250 gallons) can be inserted into the tank  15 . A selected amount of compost (preferably approximately 2 gallons, or about 8 liters) can be placed on the inside of the filter  80 . The filter  80  can then be clamped onto the dome  70  by securing the band clamp  85  onto the exterior surface of the dome  70  above the lip  73 , as shown in  FIG. 8A . The extraction assembly  60  can then be put in place within the tank  15 , as shown in  FIG. 8B . This is preferably accomplished by the user holding onto the handle  75  and connecting the top  66  of the extraction aerator  65  to the yoke  57  of the extractor head  55 . Since the extraction aerator  65  and the extraction head  55  are rigid components, the extraction assembly  60  is held in its selected location within the tank  15 . In the preferred location, at least the lip  73  at the bottom of the dome  70  is submerged within the liquid  1  in the tank  15 . The entire dome  70  can be submerged in the liquid, as shown in  FIG. 8B . 
     With the extraction assembly  65  secured in place within the tank  15 , the blower  36  can be activated. Operation of the aeration assembly  60  is schematically shown in  FIG. 8B . The blower  36  draws in filtered air  2  through the air filter  37  and moves the air  2  to tube  38 . Tube  38  splits into two tubes; tube  39  for the base aerator  50  and tube  41  for the extractor head  55 . Valve  40  can be opened to allow air  2  to exit the holes  53  in the lateral tube  52  of the base aerator  50  at the bottom  21  of the tank  15 . Valve  42  can be opened to allow air  2  to enter the extraction aerator  65 . The air  2  in the extraction aerator  65  exits into the filter  80  by exiting holes  68  near the bottom  67  of the extraction aerator  65 . 
     Continuing with  FIG. 8B , large particles  4  of the compost  3  are represented by “o”, and the microorganisms  5  are represented by “x”. Air  2  entering the extraction assembly  60  mixes with the compost  3  and liquid  1  in the filter  80  as the air rises through the filter. Some of the compost  3  rises with the air into the region  74  defined by the dome  70 . Vigorous mixing occurs in the dome  70 . Bidirectional movement of the air causes the vigorous jostling. That is, the air  2 , being less dense than the liquid  1 , tends to rise in the liquid. However, the dome captures the rising air and causes the air to redirect downward so that it can exit the extraction assembly  60  through the filter  80 . The vigorous mixing accelerates the separation of the microorganisms  5  from the larger particles  4  in the compost  3 . The greater the separation of microorganisms  5  from the larger particles  4 , the more efficient the extractor can be. 
     Generally, approximately the same amount of air that enters the extraction assembly  60  must also exit the extraction assembly in a given amount of time. The only way for the air  2  to exit the extraction assembly  60  is through the filter  80 . Air  2  leaving the filter  80  causes a current, or flow, of air  2 , liquid  1  and small particles to exit the filter  80  through the holes  82  at or near the top  83  of the filter. Liquid can be drawn into the filter  80  near the bottom  84  of the filter to replenish the liquid exiting the filter  80  near the top  83 . This contributes to the mixing of the liquid  1 , air  2 , and compost  3  in the extraction assembly  60 . The natural tendency of the air  2  to continually rise in the liquid  1  causes the air to enter the region  74  of the dome  70  for vigorous bidirectional mixing. 
     The microorganisms  5  that are extracted from the extraction assembly  60  can aerobically grow and multiply in the aerated tank  15 . Selected types and amounts of microbial food can be added to the tank  15  to aid in this growth. It is noteworthy that large particles  4  remain in the extraction assembly  60  and are incapable of passing through the filter  80 . It has been found beneficial to run the extraction process for approximately 20-24 hours to achieve a solution having high numbers of microorganisms. After that point, valve  42  can be closed and the extraction assembly  60  can be removed. The extraction assembly  60  is removed by disconnecting the extraction aerator  65  from the yoke  57  of the extraction head  55  and using the handle  75  to lift the extraction assembly  60  from the tank  15 . The tea can be kept in the tank for approximately four days so long as the fan  36  stays on and valve  40  stays open. The tea can be drained from the tank  15  through orifice  22 . 
     Turning attention now to a second preferred embodiment of the present invention, an extraction and aeration apparatus  110  is provided. This alternative preferred embodiment is shown in  FIGS. 10-12 . The apparatus  110  has a tank  115 , a fan assembly  135 , a base aerator  150 , a first extractor head  155 , a second extractor head  255 , a first extraction assembly  160 , and a second extraction assembly  260 . These components are described in detail below. 
     The tank  115  has a first side  116  and an opposed second side  117 , and has sides  118  and  119  between the front  116  and rear  117 . The tank  115  also has a top  120  and a bottom  121 . The sides  116 ,  117 ,  118  and  119 , and the top  120  and bottom  121  preferably define a generally box shaped tank having a radiused bottom, with interior dimensions approximately 80 inches wide, by 46 inches deep, by 42 inches tall. The bottom of the tank  115  is preferably radiused along a longitudinal axis as shown in  FIG. 10 . The radiused edges help eliminate havens where harmful microorganisms could otherwise flourish. Tank  115  is preferably supported with supports (not shown) that provide stability to the tank bottom to eliminate rotational movement of the radiused tank bottom. The tank preferably has a volume sufficient to hold at least approximately 500 gallons of liquid  1 . It is understood that the shape and particular dimensions of the tank  115  can vary without departing from the broad aspects of the present invention. The tank  115  is preferably made of stainless steel. In the preferred embodiment, an exit orifice  122  is located on the side  117  of the tank  115  near the bottom  121 . The orifice  122  is used to drain the contents of the tank  115 , and accordingly has a valve used to selectively open and close the orifice. Tank  115  has covers  126  and  127  on the top  120 . Covers  126  and  127  are preferably hinged, and can swing upwards as shown in  FIG. 10 . 
     The fan assembly  135  preferably is located on top of the tank  115  between the covers  126  and  127 . The fan assembly  135  preferably has a fan  136 , or blower, and an air filter  137 . The fan  136  is preferably capable of moving 60 cfm of air  2 . A tube  138  is connected to the fan  136 . The tube  138  splits to three tubes  139 ,  141  and  143 . Tube  139  can be selectively opened and closed with valve  140 . Tube  141  can be selectively opened and closed with valve  142 . Tube  143  can be selectively opened and closed with valve  144 . Tubes  139 ,  141  and  143  can be made with steel or of flexible tubing. Tubes  138  and  139  preferably have a diameter of approximately 2 inches. Tubes  141  and  143  preferably have a diameter of approximately 1.5 inches. While the tubes  138 ,  139 ,  141  and  143  are shown to be generally circular in shape, it is understood that the tubes could also be other shapes, such as square. 
     The base aerator  150  has a depth tube  151  and a lateral base tube  152 . The depth tube  151  is preferably substantially vertical, and has a preferred diameter of approximately 2 inches. The lateral base tube  152  is preferably substantially horizontal and located near the bottom  121  of the tank  115  equidistant between the sides  118  and  119  of the tank  115 . Base tube  152  preferably has a diameter of approximately 2 inches. The lateral tube  152  has ends that are preferably located equidistant from where the lateral tube  152  connects with the depth tube  151 . Several openings  153  are located through the base tube  152  to allow the air to escape into the tank  115 . The openings  153  are preferably through the bottom of the tube  152 , but could be through other sections of the tube without departing from the broad aspects of the present invention. While the base tube  152  is shown to have a generally circular shape, it is understood that is can also have other shapes. In the illustrated embodiment, the base aerator  150  is integral with tube  139 . Base aerator  150  preferably has an aeration rate of approximately 44 cfm. It is understood that the base aerator  150  could have a larger or smaller aeration rate without departing from the broad aspects of the present invention. 
     The first extractor head  155  is connected to tube  141 . The extractor head  155  preferably comprises a generally vertical tube  156 . Tube  156  has a top and a bottom. The bottom of the tube  156  preferably has a yoke  157  for removeably connecting to another tube (discussed below). The extractor head  155  preferably has a diameter of approximately 1.5 inches. It is understood that the extractor head  155  could have a different size and shape without departing from the broad aspects of the present invention. 
     The first extraction assembly  160  defines a container  161 . The container  161  has a top portion and a bottom portion. In a preferred embodiment, the container  161  has a volume of four to five gallons. However, the container  161  could be larger or smaller without departing from the broad aspects of the present invention. The container  161  is sized to hold a selected amount of compost  3  or other material. The extraction assembly  160  is removeably connected to the extractor head  155 . In this regard, the extraction head  155  holds the extraction assembly  160  in an intended location within the tank  115 . The extraction assembly  160  generally comprises an extraction aerator  165 , a dome  170  and a filter  180 , each of which are described in detail below. 
     The extraction aerator  165  has a top  166  and a bottom  167 . Openings  168  are located near the bottom  167  for allowing air to exit the extraction aerator  165  during use. The extraction aerator  165  is preferably a straight and tubular shaped and has a diameter of approximately 1.5 inches. However, it is understood that the extraction aerator could have other shapes or sizes. The extraction aerator  165  is preferably rigid, and is preferably made of stainless steel. The top  166  of the extraction aerator  165  removeably connects to yoke  157  of the first extractor head  155 . An end cap  169  is preferably at the bottom  167  of the extraction aerator  165 . The end cap  169  can be removed from the bottom  167  to allow for cleaning of the extraction aerator  165 . Extractor aerator  165  preferably has an aeration rate of approximately 8 cfm. However, it is understood that the aeration rate could be greater or smaller without departing from the broad aspects of the present invention. 
     The dome  170  has a top  171  and a sidewall  172 . The sidewall  172  has a top and a bottom. The top  171  and sidewall  172  have an interior surface and an exterior surface. A lip  173  preferably surrounds the sidewall  172  at the bottom exterior surface of the sidewall. The interior of the dome  170  defines an interior region  174 , or simply region. A handle  175  can optionally be connected to the outside surface of the dome. The dome is preferably made of stainless steel. In the illustrated embodiment, the extraction aerator  165  passes through the center of the dome  160 . It is understood that the extraction aerator  165  could extend around the outside of the dome without departing from the broad aspects of the present invention. While the dome shape has been found to be a preferred shape, other shapes are possible. 
     A preferred filter  180  is a mesh bag  181 . The mesh bag  181  has openings  182  preferably sized approximately 400 microns. However, the openings  182  could be between about 250 and 841 microns (20 to 60 mesh) without departing from the broad aspects of the present invention. The mesh bag  181  further has a top  183  and a bottom  184 , an interior surface and an exterior surface. The bag  181  preferably has an interior capacity of approximately 4 gallons. A clamp  185  is preferably located at the top  183  of the bag  181 . The clamp  185  can be a band clamp, and it is used to removeably secure the bag  181  to the dome  170  by tightening onto the exterior surface of the dome  170  above the lip  173 . The extraction aerator  165  preferably extends to near the bottom  184  of the bag  180 , and passes through the interior of the bag. Alternatively, a rigid filter such as a wire mesh cage could be used without departing from the broad aspects of the present invention. Further alternatively, the extraction aerator could pass around the exterior of the filter  180  and have an opening at the bottom  184  of the filter. The filter  180  can be a single-use filter or a reusable filter. 
     The second extractor head  255  is connected to tube  143 . The extractor head  255  preferably comprises a generally vertical tube  256 . Tube  256  has a top and a bottom. The bottom of the tube  256  preferably has a yoke  257  for removeably connecting to another tube (discussed below). The extractor head  255  preferably has a diameter of approximately 1.5 inches. It is understood that the extractor head  255  could have a different size and shape without departing from the broad aspects of the present invention. 
     The second extraction assembly  260  defines a container  261 . The container  261  has a top portion and a bottom portion. In a preferred embodiment, the container  261  has a volume of four to five gallons. However, the container  261  could be larger or smaller without departing from the broad aspects of the present invention. The container  261  is sized to hold a selected amount of compost  3  or other material. The extraction assembly  260  is removeably connected to the extractor head  255 . In this regard, the extraction head  255  holds the extraction assembly  260  in an intended location within the tank  115 . The extraction assembly  260  generally comprises an extraction aerator  265 , a dome  270  and a filter  280 , each of which are described in detail below. 
     The extraction aerator  265  has a top  266  and a bottom  267 . Openings  268  are located near the bottom  267  for allowing air to exit the extraction aerator  265  during use. The extraction aerator  265  is preferably a straight and tubular shaped and has a diameter of approximately 1.5 inches. However, it is understood that the extraction aerator could have other shapes or sizes. The extraction aerator  265  is preferably rigid, and is preferably made of stainless steel. The top  266  of the extraction aerator  265  removeably connects to yoke  257  of the second extractor head  255 . An end cap  269  is preferably at the bottom  267  of the extraction aerator  265 . The end cap  269  can be removed from the bottom  267  to allow for cleaning of the extraction aerator  265 . Extractor aerator  265  preferably has an aeration rate of approximately 8 cfm. However, it is understood that the aeration rate could be greater or smaller without departing from the broad aspects of the present invention. 
     The dome  270  has a top  271  and a sidewall  272 . The sidewall  272  has a top and a bottom. The top  271  and sidewall  272  have an interior surface and an exterior surface. A lip  273  preferably surrounds the sidewall  272  at the bottom exterior surface of the sidewall. The interior of the dome  270  defines an interior region  274 , or simply region. A handle  275  can optionally be connected to the outside surface of the dome. The dome is preferably made of stainless steel. In the illustrated embodiment, the extraction aerator  265  passes through the center of the dome  260 . It is understood that the extraction aerator  265  could extend around the outside of the dome without departing from the broad aspects of the present invention. While the dome shape has been found to be a preferred shape, other shapes are possible. 
     A preferred filter  280  is a mesh bag  281 . The mesh bag  281  has openings  282  preferably sized approximately 400 microns. However, the openings  282  could be between about 250 and 841 microns (20 to 60 mesh) without departing from the broad aspects of the present invention. The mesh bag  281  further has a top  283  and a bottom  284 , an interior surface and an exterior surface. The bag  281  preferably has an interior capacity of approximately 4 gallons. A clamp  285  is preferably located at the top  283  of the bag  281 . The clamp  285  can be a band clamp, and it is used to removeably secure the bag  281  to the dome  270  by tightening onto the exterior surface of the dome  270  above the lip  273 . The extraction aerator  265  preferably extends to near the bottom  284  of the bag  280 , and passes through the interior of the bag. Alternatively, a rigid filter such as a wire mesh cage could be used without departing from the broad aspects of the present invention. Further alternatively, the extraction aerator could pass around the exterior of the filter  280  and have an opening at the bottom  284  of the filter. The filter  280  can be a single-use filter or a reusable filter. 
     Turning to the operation of the illustrated alternative embodiment of the present invention, selected amount of water (preferably approximately 500 gallons) can be inserted into the tank  115 . A selected amount of compost (preferably approximately 2 gallons, or 8 liters) can be placed on the inside of each filter  180  and  280 . Filter  180  can then be clamped onto the dome  170  by securing the band clamp  185  onto the exterior surface of the dome  170  above the lip  173 . Filter  280  can then be clamped onto the dome  270  by securing the band clamp  285  onto the exterior surface of the dome  270  above the lip  273 . Next, extraction assemblies  160  and  260  can be put in place within the tank  115 . This is preferably accomplished by the user holding onto the handle  175  and connecting the top  166  of the extraction aerator  165  to the yoke  157  of the extractor head  155 , and by holding onto the handle  275  and connecting the top  266  of the extraction aerator  265  to the yoke  257  of the extractor head  255 . Since the extraction aerators  165  and  265  and the extraction heads  155  and  255  are rigid components, the extraction assemblies  160  and  260  are secured in their respective selected locations within the tank  115 . In the preferred location, at least the lips  173  and  273  at the bottom of the domes  170  and  270 , respectively, are submerged within the liquid in the tank  115 . The entire domes  170  and  270  can be submerged in the liquid. 
     With the extraction assemblies  165  and  265  secured in place within the tank  115 , the blower  136  can be activated. The blower  136  draws in filtered air  2  through the air filter  137  and moves the air  2  to tube  138 . Tube  138  splits into three tubes; tube  139  for the base aerator  150  tube  141  for the first extractor head  155 , and tube  143  for the second extractor head  255 . Valve  140  can be opened to allow air  2  to exit the holes  153  in the lateral tube  152  of the base aerator  150  at the bottom  121  of the tank  115 . Valve  142  can be opened to allow air  2  to enter the first extraction aerator  165 . The air  2  in the extraction aerator  165  exits into the filter  180  by exiting holes  168  near the bottom  167  of the extraction aerator  165 . Valve  144  can be opened to allow air  2  to enter the second extraction aerator  265 . The air  2  in the extraction aerator  265  exits into the filter  280  by exiting holes  268  near the bottom  267  of the extraction aerator  265 . 
     Air  2  entering the first extraction assembly  160  mixes with the compost  3  and liquid  1  in the filter  180  as the air rises through the filter. Some of the compost  3  rises with the air into the region  174  defined by the dome  170 . Vigorous mixing occurs in the dome  170 . Bidirectional movement of the air causes the vigorous jostling. That is, the air  2 , being less dense than the liquid  1 , tends to rise in the liquid. However, the dome captures the rising air and causes the air to redirect downward so that it can exit the extraction assembly  160  through the filter  180 . The vigorous mixing accelerates the separation of the microorganisms  5  from the larger particles  4  in the compost  3 . 
     Generally, approximately the same amount of air that enters the extraction assembly  160  must also exit the extraction assembly in a given amount of time. The only way for the air  2  to exit the extraction assembly  160  is through the filter  180 . Air  2  leaving the filter  180  causes a current, or flow, of air  2 , liquid  1  and small particles to exit the filter  180  through the holes  182  at or near the top  183  of the filter. Liquid can be drawn into the filter  180  near the bottom  184  of the filter to replenish the liquid exiting the filter  180  near the top  183 . This contributes to the mixing of the liquid  1 , air  2 , and compost  3  in the extraction assembly  160 . The natural tendency of the air  2  to continually rise in the liquid  1  causes the air to enter the region  174  of the dome  170  for vigorous bidirectional mixing. 
     Air  2  entering the second extraction assembly  260  mixes with the compost  3  and liquid  1  in the filter  280  as the air rises through the filter. Some of the compost  3  rises with the air into the region  274  defined by the dome  270 . Vigorous mixing occurs in the dome  270 . Bidirectional movement of the air causes the vigorous jostling. That is, the air  2 , being less dense than the liquid  1 , tends to rise in the liquid. However, the dome captures the rising air and causes the air to redirect downward so that it can exit the extraction assembly  260  through the filter  280 . The vigorous mixing accelerates the separation of the microorganisms  5  from the larger particles  4  in the compost  3 . 
     Generally, approximately the same amount of air that enters the extraction assembly  260  must also exit the extraction assembly in a given amount of time. The only way for the air  2  to exit the extraction assembly  260  is through the filter  280 . Air  2  leaving the filter  280  causes a current, or flow, of air  2 , liquid  1  and small particles to exit the filter  280  through the holes  282  at or near the top  283  of the filter. Liquid can be drawn into the filter  280  near the bottom  284  of the filter to replenish the liquid exiting the filter  280  near the top  283 . This contributes to the mixing of the liquid  1 , air  2 , and compost  3  in the extraction assembly  260 . The natural tendency of the air  2  to continually rise in the liquid  1  causes the air to enter the region  274  of the dome  270  for vigorous bidirectional mixing. 
     The microorganisms  5  that are extracted from the extraction assemblies  160  and  260  can aerobically grow and multiply in the aerated tank  115 . Selected types and amounts of microbial food can be added to the tank  115  to aid in this growth. It is noteworthy that large particles remain in the extraction assemblies  160  and  260  and are incapable of passing through the respective filters  180  and  280 . It has been found beneficial to run the extraction process for approximately 20-24 hours to achieve a solution having high numbers of microorganisms. After that point, valves  142  and  144  can be closed and the extraction assemblies  160  and  260  can be removed. The extraction assemblies  160  and  260  is removed by disconnecting the extraction aerators  165  and  265  from the yokes  157  and  257  of the respective extraction heads  155  and  255 , and using the handles  175  and  275  to lift the respective extraction assemblies  160  and  260  from the tank  115 . The tea can be kept in the tank  115  for approximately four days so long as the fan  136  stays on and valve  140  stays open. The tea can be drained from the tank  115  through orifice  122 . 
     Thus it is apparent that there has been provided, in accordance with the invention, an aeration and extraction assembly and a method of extracting and growing compost tea that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.