fig1 illustrates one embodiment of a fluid flow control assembly according to the present invention . the fluid flow control assembly comprises a body of two pieces ( 104 , 114 ) which may be of plastic or metal . the body ( 104 , 114 ) defines an internal chamber ( 102 ). at one end is an inlet aperture ( 112 ) and at the distal end an outlet ( 101 ) through the device is non - directional and may be used either way around ( e . g . aperture ( 101 ) may be the inlet )). within the internal chamber ( 102 ) is a baffle arrangement ( generally indicated by arrow 115 ) comprising a plurality of baffle elements ( 103 ). each baffle element ( 103 ) comprises a plate - like element having a raised annular ridge ( 105 ) defining a recessed central cavity region ( 106 ). apertures ( 109 ) and ( 110 ) are placed in alternate positions to make the flow of fluid through the baffle elements ( 103 ) more tortuous . additionally or instead of apertures ( 109 , 110 ), channels ( 108 ) in the outer edge of each element may be provided to let fluid flow past each baffle element ( 103 ). fig2 illustrates a preferred embodiment of a fluid flow control assembly comprising a body ( 204 ) defining an internal chamber ( 208 ). within this chamber ( 208 ) two differing embodiments of a baffle arrangement ( 210 a , 210 b ) are illustrated . the first baffle arrangement ( 210 a ) comprises a sequence of baffle elements ( 202 ) each comprising a spherical bead of slightly smaller diameter than that of the internal chamber . each bead is linked by a restraining element ( 203 ) comprising a wire . the wire is terminated at each end ( 211 a , 211 b ) to retain the beads ( 202 ). the terminations are further apart than the sum of the diameters of the beads ( 202 ) thereby allowing their individual movement along the direction of the wire ( 203 )— i . e . the longitudinal direction — while the smaller diameter of the beads ( 202 ) relative to the internal chamber also means they can move perpendicularly to the longitudinal as well . this relative freedom of movement , as well as being able to rotate about the wire ( 203 ) helps provide sufficient movement for the baffle elements ( 202 ) to be self - clearing of minor foreign particles and air bubbles , or to adjust in position to still allow fluid flow through the fluid flow control assembly . the second baffle arrangement ( 210 b ) is similar to the first ( 210 a ) except separating elements ( 233 ) are placed on the wire ( 203 ) between each larger size baffle element ( 232 ). for comparison , the baffle elements ( 232 ) may be the same as elements ( 202 ) in the first baffle arrangement ( 210 a ). the general principles of operation of this second baffle arrangement ( 210 b ) are generally the same as discussed for first baffle arrangement ( 210 a ). please note also that fig2 is not to scale and is for illustrative purposes . in practice the diameter of the larger baffle elements ( 202 , 232 ) will be relatively close to that of the internal diameter of internal chamber ( 208 )— see below for some typical dimensions of a preferred embodiment . as can be seen the restrictions ( 220 ) of the baffle arrangement ( 210 ) occur where the diameter of the beads ( 202 , 232 ) is greatest , while the cavity represents the volume ( 221 ) of reducing diameter defined between adjacent beads . the internal diameter of the internal chamber ( 208 ) for an animal trough application is typically from 8 through 15 mm in diameter . the diameter of the beads is typically 0 . 75 through 2 mm less than the diameter of the internal chamber . typically 8 through 12 beads ( 202 , 232 ) are used , with an average individual free - play ( longitudinally ) of 0 . 5 to 3 times the difference in diameter between the beads ( 20 , 2322 ) and internal chamber ( 208 ). at one end is an inlet ( 201 ) and near the distal end a dual outlet ( 205 ). the fluid flow control assembly is , again , non - directional and may be connected either way around . fig3 illustrates an embodiment of a dispenser for use in an inline dosing arrangement . the dispenser comprises a body ( 301 ) of 300 mm diameter pipe sectioned off ( 302 ) to provide a dosing chamber ( 303 ) and additive reservoir ( 304 ). the approximate size of the dosing chamber is 5 litres , while the additive chamber is 30 - 50 litres . a chamber to reservoir pipe ( 310 ) allows fluid to travel from the dosing chamber ( 303 ) to additive reservoir ( 304 ). at the dosing chamber end of this pipe is a fluid flow control assembly ( 305 ) regulating the flow of fluid through this pipe ( 310 ). return flow from the reservoir ( 304 ) to dosing chamber ( 303 ) is via reservoir to chamber pipe ( 311 ) which also has a fluid flow control assembly ( 306 ) at the dosing chamber end to regulate fluid flow further . apertures ( 312 ) in the reservoir to chamber pipe ( 311 ) allow a more even flow of treated fluid back into the dosing chamber ( 303 ). a filter gauze may ( not shown ) map be placed over the apertures ( 312 ) to help prevent foreign material and solid additive from reaching the fluid flow control assembly ( 306 ). similar apertures ( to 312 ) may also be provided of the reservoir side of chamber to reservoir pipe ( 310 ). a filler cap ( 340 ) allows additive to be added to the additive reservoir ( 304 ). ideally the additive is of a type which allows fluid to permeate through the settled mass , so as not to clog pipes ( 310 ) and ( 311 ) though other pipe designs may be used if clogging is a potential issue . preferred additive types to prevent clogging of the illustrated embodiment are granular , crystalline , capsular , agglomerates , tablets , gelled particles , etc . ( as opposed to free fine and microfine powders which could be problematic in the illustrated embodiment &# 39 ; s design ) where higher dosing rates are required , a bypass valve ( 314 ) ( controllable from outside the dosing chamber ) may be provided to bypass the fluid flow control assembly ( 305 ) and allow chamber to reservoir pipe ( 310 ) to draw fluid directly ( 333 ) from the dosing chamber ( 303 ). a fluid inlet ( 320 ) is connected by hose ( 321 ) to a valve coupling ( 322 ) to pipeline ( 323 ). downstream a further valve coupling ( 324 ) returns additive treated fluid to the pipeline ( 323 ), and is connected by hose ( 325 ) to an outlet ( 326 ) from the dosing chamber ( 303 ). a restrictor ( 329 ) may be placed in the pipeline ( 323 ) between couplings ( 323 ) and ( 324 ), and may take the form of a flow control valve . fig4 illustrates a floating dispenser which may be used in a vat or animal trough . in this embodiment the dosing chamber ( 13 ) is formed by a closed pipe section ( 14 ). fluid from the trough enters upwardly through size restricted conduit ( 6 ) which leads into a distribution pipe ( 10 ) with a plurality of apertures ( 11 , 12 ) therein to introduce the fluid evenly into the chamber ( 13 ). apertures ( 15 ) in the wall ( 16 ) of the dosing chamber ( 13 ) allow fluid to pass into the reservoir ( 2 ) to mingle with additive ( 21 ). a concentration gradient with a heavier lower layer ( 22 ) forms and this heavier fluid slowly flows back into the dosing chamber ( 13 )— the flow arrows illustrate the typical flow of fluid in the system . the heavier treated fluid collects at the bottom of the dosing chamber ( 13 ) and flows through conduit ( 7 ) whereupon it encounters fluid flow control assembly ( 19 ) before exiting via outlet ( 20 ). the fluid flow control assembly regulates the flow of heavier treated fluid more effectively ( and less problematically ) than a fine aperture . it is noted that the a fluid flow control assembly can also , or instead , be connected to the inlet ( 9 ) of conduit ( 6 ) for further flow regulation of fluid into and out of the dispenser . the outlet ( 20 ) may also have a filter gauze , rather than a restricted outlet aperture , to prevent backwash of contaminants into the system during refilling and use , or may be omitted altogether . aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the spirit or scope of the present invention as described herein . it should also be understood that the term “ comprise ” where used herein is not to be considered to be used in a limiting sense . accordingly , ‘ comprise ’ does not represent nor define an exclusive set of items , but includes the possibility of other components and items being added to the list . this specification is also based on the understanding of the inventor regarding the prior art . the prior art description should not be regarded as being authoritative disclosure on the true state of the prior art but rather as referencing considerations brought to the mind and attention of the inventor when developing this invention .