referring now specifically to the drawings , fig1 shows the inventive drip irrigation / fertilization filter , which is generally designated herein with the reference numeral 10 . irrigation filter 10 is comprised of a reservoir 12 , a liquid outlet control means , and a liquid inlet control means . as shown in fig1 reservoir 12 comprises a side wall 20 that is generally continuous and often a slightly tapered cylinder , although other configurations , shapes and sizes of reservoir 12 are contemplated to be within the realm of this disclosure . the side wall terminates in an upper rim 22 and a bottom 24 . for portability , an optional handle 26 is often included , which is connected to the outside of side wall 20 by standard means . formed into the reservoir &# 39 ; s bottom 24 is a single aperture 28 , the diameter of which is variable and selected to accommodate the particular reservoir volume and desired delivery rate . the diameter of aperture 28 is often between about one - half inch to one - eighth inch , but may be smaller or larger if needed . the aperture may be directly formed in reservoir bottom 24 during fabrication or later by drilling , punching , melting , and equivalent methods . although not mandatory , preferably reservoir 12 is formed as a single unit with rim 22 , bottom 24 , and side wall 20 connected into a seamless piece . reservoir 12 is fabricated from water insoluble material such as natural or synthetic polymers , and non - corrosive metals and metal alloys . traditionally shaped buckets , inexpensive or discarded plastic pails , or more aesthetically pleasing containers are all suitable for serving as a reservoir for the present invention . the liquid outlet means comprises a porous support member 14 , a 3 - piece primary filter member 16 , and layer of particulate matter 17 . as shown in fig2 and 3 , porous support member 14 has a top surface 13 , a bottom surface 15 , a perimeter edge , and is generally planar in shape , although other shapes , such as concave and convex , are contemplated . typically , porous support member 14 is approximately 21 to 22 inches in diameter , and approximately 1¼ inches thick , although different sizes are contemplated depending upon the size of reservoir 12 . as shown in fig1 , and 3 , porous support member top surface 13 has a centrally located recess , which is approximately 3 inches in diameter and { fraction ( 1 / 16 )} inch deep . porous support member bottom surface 15 has a centrally located recess , which is approximately 6 inches in diameter and one - half inch in depth . porous support member 14 is sized to fit within reservoir 12 , proximate reservoir bottom 24 , and is positioned within reservoir 12 directly on top surface 23 of reservoir bottom 24 . porous support member 14 is typically made from a mixture of # 6 large grain sand and a binding material such as portland cement or a resin . primary filter member 16 comprises a top portion 30 , a bottom portion 32 , and a filter screen 34 . as shown in fig4 and 5 , bottom surface 42 and top surface 36 of bottom portion 32 contain a plurality of grooved channels 38 , which are directed toward a single aperture 40 located in the center of bottom portion 32 . as shown in fig4 , 7 and 8 , bottom portion 32 and top portion 30 contain a plurality of aligned , hexagonally shaped , peripherally located apertures 44 , and peripherally located spacers 46 . as shown in fig6 and 8 , filter screen 34 contains a plurality of apertures 48 . apertures 40 and 44 are approximately ¼ inch in diameter , although different sizes are anticipated depending upon constructions preferences . as shown in fig1 bottom surface 42 of bottom portion 32 sits directly atop porous support member top surface 13 . filter screen 34 sits directly atop top surface 36 of bottom portion 32 . top portion 30 sits directly atop filter screen 34 . as shown in fig8 the 3 - piece assembly , comprising bottom portion 32 , filter screen 34 , and top portion 30 , is sealed into one unit by inserting attachment means 50 into aligned , hexagonally shaped , peripherally located plurality of apertures 44 and snapping the 3 - piece primary filter member unit together . silicone or some other suitable sealant is placed around the outer edge of primary filter member 16 to attach primary filter member 16 to the inside of reservoir side wall 20 . bottom portion 32 and top portion 30 are made of plastic , and filter screen 34 is made of a nylon - coated , decay - resistant synthetic or natural polymer material . the thickness of filter screen 34 and the type of material from which filter screen 34 is fabricated are selected to permit a desired liquid flow rate . as shown in fig1 layer of particulate matter 17 sits directly atop primary filter member 16 . typically , layer 17 is comprised of loose # 8 sand , gravel , and the like , which are selected for their ability to pass a desired amount of liquid in a given period of time . particle size within particulate matter 17 and interactive characteristics between the particles within the particulate matter determines the liquid flow rate . the size of the particles comprising the particulate matter are selected to have a size too large to pass through underlying primary filter member 16 . generally , for any one type of particulate matter 17 , the thicker the layer of particulate matter 17 , the slower the passage of liquid . depending upon the desired liquid flow rate , the thickness of layer 17 is varied . layer 17 must have a compositional structure that permits the flow of liquid but prevents the passage of particulate matter 17 . as shown in fig9 the preferred embodiment of the liquid inlet control means comprises float 51 , connecting arm 52 , and inlet / shut - off valve 54 . cover 18 comprises bottom surface 60 and top surface 62 . attached to bottom surface 60 and extending through top surface 62 is valve 54 . one end of connecting arm 52 engages valve 54 , while the opposite end of connecting arm 52 is attached to float 51 . optionally attached to top surface 62 is pipe attachment 56 , which can be connected at one end to valve 54 and terminate in hose fitting 58 . hose fitting 58 may be connected to an external liquid source . alternatively , liquid may be added to reservoir 12 , manually . cover 18 may also be adapted to include a perimeter overhang 21 extending beyond reservoir side wall 20 to help shade reservoir 12 and its contents from direct sun exposure . cover 18 and float 51 are made of plastic . connecting arm 52 , pipe attachment 56 , and hose fitting 58 are made of rust resistant metals or metal alloys . as shown in fig1 , an additional embodiment of the inlet control means comprises float 51 a , connecting stem 52 a , and inlet / shut - off value 54 a . cover 18 a comprises outer surface 62 a and inner surface 60 a . outer surface 62 a is cone shaped and terminates in peak 64 . attached at peak 64 is inlet / shut - off valve 54 a . one end of connecting stem 52 a engages inlet / shut - off valve 54 a , while the opposite end of connecting stem 52 a is attached to float 51 a . a standard garden hose or other external water source may be attached to inlet / shut - off valve 54 a at peak 64 . in function , the subject device is often used in tree orchards , or similar agricultural environments , which require the watering and fertilization of multiple trees or plants . however , the alternative embodiment of the inlet control means , along with a smaller reservoir , may be more aesthetically pleasing and suitable for use with home gardens , commercial and public landscapes , and other non - agricultural settings . generally , an individual device is placed directly on the soil near the base of each tree or plant , and in any available shade . although water may be added to each device manually , usually in practice each device is directly connected to a water hose or pipe , which is equipped with a timer or an equivalent means for regulating the periods in which water is supplied to the hose . during periods in which water is supplied to the hose , the reservoir fills to the cut - off level and is maintained at that level via the inlet / shut - off valve . about a 45 minute filling cycle is common , but other time intervals are acceptable and depend on various factors , including plant type , soil type , and reservoir volume . the liquid within the reservoir percolates down through the particulate layer , through the primary filter member and support member , and out of the single aperture on the reservoir bottom . to increase or decrease liquid delivery , the type or thickness of filter screen and particulate matter can be adjusted . fertilizer and other nutrients may be placed either directly within the reservoir or , more commonly , directly beneath the reservoir . the stream of exiting drips slowly dissolves the nutrients for transportation into the soil and plant or tree roots . several advantages result from the disclosed device . most significantly , algae is less likely to grow on the decay resistant screen because employing layers of particulate matter both above and below the primary filter member prevents light from penetrating the primary filter member . moreover , the porous support member sits directly on the reservoir &# 39 ; s bottom , as opposed to being elevated by spacers , which further impedes light entry into the reservoir . in addition , the reservoir &# 39 ; s bottom contains only one exit aperture , instead of a plurality of exit apertures , thus diminishing the number of potential light entry points . also , the reservoir cover may be adapted with a perimeter overhang , which assists in preventing light entry into the reservoir . the primary filter member is more durable than conventional filters , and is better equipped for use in a variety of agricultural and commercial growing settings , including muddy irrigation ditches . using the decay resistant filter screen instead of conventional paper or cloth filters enables the device to filter very muddy water for long time periods between filter cleanings and changes . sealing the primary filter member to the reservoir &# 39 ; s inside wall prevents unfiltered liquid from leaking through the device onto soil . the present invention also promotes water conservation while effectively hydrating tree and plant roots by dripping liquid , which may be regulated to achieve varying volume delivery rates , one droplet at a time , through the reservoir &# 39 ; s one centrally located aperture , which subsequently fans out and hydrates all roots efficiently . this hydration method avoids water waste associated with evaporation and the inadvertent watering of weeds and nearby objects that do not require watering . and finally , the heavy porous support member acts not only as a filter , but also as a ballast by stabilizing the reservoir and its contents , which obviates the need for a stand or other apparatus to hold the reservoir in place during use . also , given the disclosed configuration of the subject invention , it is easily transported and disassembled for cleaning , and is relatively inexpensive in construction . the foregoing detailed disclosure of the inventive irrigation / fertilization filter apparatus 10 is only illustrative of the preferred embodiment of the invention , and is not a limitation upon the invention &# 39 ; s scope . those skilled in the art will envision many other possible variations of the structure disclosed herein , which nonetheless fall within the scope of the following claims . for example , reservoir 12 and its contents may be larger or smaller to accommodate different liquid volumes , and constructed in different shapes and sizes depending upon placement requirements . consequently , the scope of the present invention should be determined with reference to the appended claims , and not by the examples that have been given herein .
an irrigation / fertilization filter apparatus for continuously supplying liquid to plants and trees , which comprises a reservoir for containing the liquid having a single exit aperture on its bottom ; a cover releasably fitted to the reservoir , which may be adapted with a hose attachment means for connection to an external water source ; an inlet control means for regulating the amount of liquid entering the reservoir ; and an outlet control means for regulating the rate at which liquid exits the reservoir . the outlet control means is situated within the reservoir and consists of a layer of particulate matter , a durable primary filter member , and a porous support , which sits directly on the reservoir &# 39 ; s bottom .