BACKGROUND

The present invention relates tc a hydroponic system. More particularly, the present invention relates to a hydroponic system comprising, (i) a series of axiaiiy aligned channels: (Ή) a gutter located below the channels; (iii) a fluid feed to the upstream end of each channel; and (iv) adjustable supports for adjusting the inclination of the floor of the channels relative to the floor of the gutter

Various hydropcnie systems are known. For instance:

WO02/063944 "Molded container for hydroponic culture and system using the same '. US4 ,976,064 "Equipment and methods for injecting aqueous nutrient solution m hydroponic culture ^" and US5.394.647 "Hydroponic plant growing system and structure ^" describe a hollow elongate body defining axiaiiy spaced apertures on its upper surface for receiving a series of baskets therein and a water tniet associated with each basket. The water is sprayed into the basket and runs substantially vertically along the vertical axis of the basket into the elongate body.

US4.334.386 "Soiless gardening system", describes a system comprising: (;} a gutter: {») a series of baskets supported above the gutter; (iii) a fluid feed for feeding fluid into the bottom of the baskets, wherein each basket defines an aperture near its upper end for discharging fluid from the basket into the gutter.

WO2012/034575 'Device and method for cultivating one or more plants". FR2.659.1 2 "Appareiiiage pour culture hors-so" DE3635530 "Zeriegbarer anzucht-und transportkasten fur kuiturplanzen", NL 1027094 "Werkwijze, kasinrichting, houder en scheidingseiement voor de teelt van eenma!ige snijbloemen ^" and US6.216,390 'Hydroponic culture procedure and device for implementing if desenbe a system comprising a channel and a gutter located below the channel, wherein the dividing wail between the gutter and channel defines a series of axiaiiy spaced primary apertures for permitting fluid communication between the channel and gutter. W02C13/082601 "Photesyntnetic grow moduie ano metnods ot use descnoes a system including, (i) a sloping elongate channel; (si) a gutter located below the channel that slopes in a direction opposite to the channel; and (iii) a fluid feed at the upstream end of the channel, wherein the downstream axia! end of the channel is in fluid communication with the gutter to discharge fluid from the channel into the gutter.

US4.310 _: 900 'Hydroponics' describes a system comprising: (i) a senes of axialiy aligned channels; (ii) a gutter located be!ow the channels; and (iii) e fluid feed associated with each channel, wherein each channel defines a series of axialiy spaced apertures permitting fluid communication between the channel and the gutter to discharge fluid from the channel to the gutter along the length of the channel.

A drawbar* of prior art systems is that the level / gradient of the channel floors relative to the level / gradient of the gutter floor is not easily adjusted to ensure optimal gradient of each channel floor for the formation of a nutriem-nch film on plant roots located within the channels

The hydropom ^' c system according to the present invention aims to provide a system that permits adjustment of the height / gradient of the channel floor relative to the height .' gradient of the gutter such that the upstream end of a downstream channel may be elevated relative to the downstream end of an adjacent upstream channel.

According to a preferred embodiment of the present invention, a hydroponic system includes: at least three channels aligned substantially axialiy relative to each other: at least one gutter located below the at least three channels; at least one fluid feed associated with each channel for. in use. feeding fluid ÷nto such channel at or near the upstream end of the channel; each channel defining a fluid outlet at or near its downstream end for. in use, discharging fluid from the channel into the gutter, and at least one first adjustable support associated with each channel for adjusting the gradient of the channel floor relative to the gradient of the gutter floor, such that fcr each pair of adjacent channels: (ii) the upstream end of each downstream channel ts operativeiy higher than the downstream end of the adjacent upstream channel, or

(ii) the upstream end of the each downstream channel is operativeiy lower than the downstream end of the adjacent upstream channel, such that the gradient of each channel is either greater or less than the gradient of the gutter. Preferably, the gradient of each channel is between 0.6 and 1.2 degrees. More preferably, between 0.8 degrees and 1 degree.

Generally each channel include* an o ^p rative upper wail that defines At least two ayia!iy spaced primary apertures for. in use. receiving plants therethrough.

Each operative upper wali may include a secondary aperture at or near its upstream end for receiving fluid from the fluid feed, which secondary aperture is located upstream of the primary apertures. Typically, each channel permits fluid communication between the channel and the gutter at or near the downstream end of the channel only.

Preferably, the axial ends of the channel are closed by end caps. Generally, the fluid feed is a pipe that runs along the gutter.

Typically, each channel includes at least two lips for supporting the channel on the operative top of the sidewails of the gutter. Preferably, the first adjustable support includes: (i) a threaded portion that may be rotated to adjust the height of the first adjustable support; or <ii} a wedge portion.

Generally, the hydroponic system further includes a first reservoir for storing fluid that is conveyed along the fluid feed to the channels

Typically, the hydroponic system further includes a second reservoir for storing fluid discharged from the gutter Preferably, the fluid is a nutrient-rich aqueous solution.

In use _: the flow of fluid through each channel may be between 8 and 13 litres per hour.

Typically, each channei is between 1m and 3m in length.

Preferably, each channei includes a first adjustable support at or near its upstream end and a first adjustable support a! or near its downstream end.

Generally, the hydroponic system further includes a second adjustable support for supporting the gutter above the ground: such that the gradient of the gutter can be adjusted

¾RI£F D£¾£R.lPTiON OF THE DRAWINGS

Tne hydroponic system will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of the hydroponic system according to the present invention:

Figure 2 is a cross- sectionai side view of the hydroponic system in Figure 1; and

Figure 3 is an exploded perspective view of the hydroponic system in Figure 1.

DESCRIPTION OF THE INVENTION

With reference to Figures 1 to 3. a hydroponic system 10 includes a gutter 12, channels 14 and fluid feeds 16.

The gutter 12 is genera!ly U-shaped in cross-section. The floor of the gutter 12 is inclined relative to tne horizontal Each gutter 12 is connected to its neighbouring gutters) 12 by a sealed fitting (not shown) Each channel 14 is typically between 1m and 3m in length (with the option of being up to 6m in length should ground elevation allow ;t). and the channels 14 are aligned substantially axiatiy relative to each other (».e with their longitudinal axes angularly offset by less than 15 degrees). Each channel 14 is generally U-shaped in cross-section and sized to be supported either above or within the gutter 12. The axial ends of the channel 14 are closed by end caps 18 and the top of the channel 14 is closed by an operative upper wail 20. The end cap 18 at the upstream axial end of the channel 14 is sealed to prevent egress of fluid, whereas the end cap 18 at the downstream axial end of the channel 14 need not be sealed, as its primary purpose is to retain solids within the channel 14. The operative upper wall defines: (i) axiatiy spaced circular or polygonal (e.g. square) primary apertures 22 for receiving plants therethrough, into the channel 14; and {») a secondary aperture 23 at or near its upstream end for receiving fluid from the fluid feed 16, which secondary aperture ?3 * located u stream of the primary apertures ?2. The floor of each channel 14 is also inclined relative to the horizontal.

The channel 14 is designed to contain fluid 24 (in the form of a nutrient-rich aqueous solution) therein, having a fluid outlet 26 (in the form of a series of apertures) at or near the downstream end of the channel 14 only (i.e. spaced from the downstream end cap 18 a distance of not more than [toe length of the channel 14} x 15%). for discharging fluid from the channel 14 into the gutter 12

The channel 14 also includes lips 28 that extend outwards from the side walls of the channel 14. which lips 28 are sized and shaped to locate over the top of the side wails of the gutter 2. thereby to support the floor of the channel 14 above the floor of the gutter 12. In addition to supporting the channel 14 above the floor of the gutter 12, the lips 28 also: (i) support tine side walls of the gutter against splaying: and limit lateral movement of the channel 14 within the gutter 12. A fluid feed 16 in the form of a pipe is associated with each channel 14 for charging the channel 14 with fluid 24 at or near the upstream end of the channel 14 (i.e. spaced from the upstream end cap 18 a distance of not more than [the length of the channel 14\ x 15%) via the secondary eperture 23. Despite terminating at the upstream end of a channel 14. the fluid feed 16 is otherwise located within the gutter 12 so as to protect it (and the fluid 24 conveyed thereby) from the sun s light rays and heat. Although each channel 14 has been described as having a single fluid outlet 26 and fluid feed 16. it will be appreciated that, for longer channels 14. a second or further fluid outlets 26 and fluid feeds 16 may be added along the length of the channels 14. Where additional fluid feeds 16 are required, the floor and upper wails 20 of the channel 14 may define additional apertures (not shown) to permit fluid feed 16 pipes to travei therethrough. Such additional apertures may serve a second purpose as a fluid outlet 26. It will also be appreciated that channels 14 may be modular, connectabie end-to end to form longer channels 14 A first adjustable support 30 is associated with each channel 14 for adjusting the gradient of the channel 14 floor reiative to the gradient of the gutter 12 floor The first adjustable support 30 could be at one or both of the upstream and downstream ends of the channel 14 Tynirall for flat terrain the gradient of the channel 14 floor is less than the gradient of the gutter 12 floor The first adjustable support 30 ensures that, for each pair of adjacent channels 14, the upstream end of the downstream channel 14 is elevated reiative to (i.e. operativeiy higher than) the downstream end of the upstream channel 14. For steeper terrain, the gradient of the channel 14 floor may be greater than the gradient of the gutter 12 floor, with the first adjustable supports 30 ensuring that, for each pair of adjacent channels 14. the upstream end of the downstream channel 14 is operativeiy lower than the downstream end of the upstream channel 14. This arrangement makes the hydroponic system 10 suitable for a wide range of terrain profiles, which reduces the need for expensive groundwork. It will be appreciated that for undulating terrain, the channels 14 in a first gutter 12 may ait have a gradient greater than the gutter 12 on which they are supported, while all the channels 14 in an adjacent second gutter may have a gradient less than the gutter on which they are supported.

The gradient of each channel 14 floor should be adjusted to be within the range 0.6 and 1.2 degrees, preferably, between 0.8 degrees and 1 degree to the horizontal plane. The first adjustable support 30 includes a threaded portion (in the form of a bolt), which may be rotated to adjust the height of the first adjustable support 30, and thereby the gradient of the channel 14 supported thereon. Alternatively, the first adjustable support 30 may include a wedge portion (not shown) that is movable to adjust the elevation of the channel 14 supported thereon. Optionally, each channel 14 includes a firs! adjustable support 30 at or near its upstream end and a first adjustable support 30 at or near tts downstream end, for fine adjustment of the gradient of the channels 14. A second adjustable support 32 supports the gutter 12 above the ground, and is adjustable to vary the gradient of the gutter 12.

A first reservoir (not shown) stores fluid 24. which is conveyed along the fluid feed(s) 16 to the upstream end of the channels 14. Fluid 24 discharged from the downstream end of the gutter 12 is stored in a second reservoir (not shown). Preferably, the gutter 12 includes an end cap at its upstream axial end. in us*, one or more channels 14 are supported above the gutter 12, and fluid 24 is conveyed from the first reservoir, via the fluid feeds 16.. into the upstream end of the channels 14 via the second aperture 23. Each fluid feed 16 typically charges its associated channel 14 with between 8 and 13 litres of fluid 24 per hour, albeit that (i) flow rates up to 30 litres per hour may be required for plants 36 with high transpiration rates: and (ii) flow rates as low as 1 litre per hour may be required for seeds Plants 36 extend through the primary apertures 22 defined by the upper wall 20. with their roots in the channels 14. The end caps 18 on the upstream axia! ends of the channels 14- (i) contain the substrate (e.g. plants or growing substrate) within the channels 14; (it) prevent the fluid 24 from flowing upstream; and (iii) shields the channels 1 from light so as to prevent the growth of algae within the channels 14. Similarly, the end caps 18 on the downstream axial ends of the channels 14 (i) contain substrate within the channels 14, and (it) shields the channels 14 from light. The flow rate within the channels 14 is regulated to ensure formation of a film (typically less than 3mm in depth to ensure sufficient oxygenation of the plant 36 roots) of nutrient-rich aqueous solution 24 around the roots of the plants 36. The fluid outlet 26 permits discharge of fluid 24 from the channels 14 into the gutter 12, which fluid 24 is conveyed along the gutter 12 to the second reservoir. Upon setup, the first adjustable support 30 is adjusted to ensure the desired gradient of the channel 14 relative to the horizontal plane. This channel 14 gradient is regularly monitored and adjusted to maintain the desired gradient upon setup and upon cleaning of the hydroponic system 10.