Abstract: The present invention provides a portable high throughput liquid filter system.

Abstract: A liquid filter device can filter liquid flowing therethrough using a granulated filter media included in a tank. The liquid filter device can perform a backwash of the granulated filter media by creating active zones and inactive zones in the tank. In the active zones, the granules are agitated and driven by a flow of liquid toward the top of the tank. In the inactive zones, the granules fall by gravity toward the bottom of the tank. The liquid filter device can include a conduit, a hub and a number of laterals, each of which may individual fit through an opening in the tank and be assembled to form a combined structure that will not fit through the opening in the tank. The active zones may be created above a top surface of each of the laterals by including slots on the top surface.

Abstract: Systems and methods condition a filter assembly. Purging liquid is passed through the filter assembly to remove contaminants from the pores and voids of the filter medium and from the upstream and downstream sides of the filter medium.

Abstract: A shower filter between a downwardly slanting shower arm and a shower head, including a base, and a vertical housing with filler material. The base has an input chamber for receiving water from the shower arm, and an output chamber from which water may be discharged to the shower head. The housing is secured at its bottom end to the base and has a first port communicating with the base input chamber and a second port communicating with the base output chamber. A tube carries water from the housing first port to the top end of the housing, where it is diffused before passing down through the filter material and second port to the output chamber. A fragrant block is mounted to the base.

Abstract: Exemplary embodiments include a unitary pool filter tank and/or an underdrain for a pool filter unit. Embodiments of the unitary pool filter tank can have an integrally formed housing and base. The filter tank can be formed using a blow molding process in which the base of the filter tank is reinforced using multiple polymer layers that have been folded and/or pinched together. Embodiments of the underdrain can be formed by interlocking top and bottom components. The top and bottom components can be interlocked by inter-component locking structures.

Abstract: A filtration and demineralization apparatus 10 including a vessel 20 in a form of a body of revolution; a hollow columnar body 40 that is located in an internal space of the vessel 20, one end 40a of the columnar body being connected to an inner surface of the vessel 20 along an entire circumference of the end, and the other end 40b of the columnar body forming an opening; and a partition plate 44 that is connected to the other end 40b of the hollow columnar body along an entire circumference of the other end 40b, the partition plate being configured to separate an inside space or an outside space of the hollow columnar body 40 as an independent space in the vessel. The partition plate 44 has a circulation port 43 that allows water that is to be treated to pass therethrough.

Abstract: A distributor for use on a dip tube in the particulate bed of a water conditioner includes a sleeve mounted on the dip tube, a plurality of resilient vanes extending radially outwardly from the sleeve, thin membranes on the vanes, and holes in the membranes, whereby water flowing through the bed is evenly distributed throughout the bed and the bed is agitated by up and down flexing of the distributor in the bed.

Abstract: A waste fluid treating apparatus including a pure water generating unit including an ion exchanger for purifying a fresh water sent by a fresh water pump to obtain a pure water. The ion exchanger includes a housing, an anion exchange resin layer accommodated in the housing, and a mixed resin layer accommodated in the housing. The anion exchange resin layer is composed of only anion exchange resin, and the mixed resin layer is composed of a mixture of anion exchange resin and cation exchange resin. The housing is provided with a fresh water inlet for introducing the fresh water into the anion exchange resin layer and a pure water outlet for discharging the pure water from the mixed resin layer.

Abstract: A tank has a side wall bounded by a top and a bottom. An axis extends vertically through the tank. An inlet line for water of a first condition extends through the top with a lower end at a lower extent of the tank. An outlet line for water of a second condition has a lower end within an intermediate extent of the tank. A dispenser at the lower end of the water inlet line has apertured legs extending radially within the tank. An oscillator within the tank above the dispenser is operatively coupled to the inlet line for mixing all of the water of a first condition entering the tank through the inlet line while thereafter forwarding all of the mixed water of a first condition to the dispenser.

Abstract: The present invention provides a flow-control support for a distributor plate in a composite pressure vessel. The distributor plate includes a thermoplastic polymeric disk having a top side, a bottom side, a perimeter edge and a central opening and a plurality of fluid flow passages through the disk. The flow-control support is disposed between the bottom side of the disk and an inner side of an end of a thermoplastic liner assembly. The flow-control support includes a spirally fluted upper surface that is adapted to direct fluid flowing from a supply pipe disposed in the central opening of a distributor plate that is supported by the flow control support such that the fluid swirls in a space between the bottom side of the distributor plate and an inner side of an end portion of a water treatment vessel. The swirling water insures that fluid is distributed to substantially all of the fluid flow passages through the disk during backwashing operations.

Abstract: The invention relates to a device 1 for treating a fluid, including a container 2,3 with inner space, at least one entrance to the inner space arranged on the container, wherein the entrance includes a first and second opening 4,5, a grid body 14 which is arranged in the inner space and which divides the inner space into a first compartment for a treatment arrangement, preferably filter material, connected to the first opening 4 and at least one second compartment which is connected by means of a tube 25 to the second opening 5 and which is free of filter material. The tube has a connector arrangement for connecting the second opening to the first compartment.

Abstract: The present invention provides: a distributor plate for a composite pressure vessel. The distributor plate includes a thermoplastic polymeric disk having a top side, a bottom side, a perimeter edge and a central opening. Radial slits are formed in the disk to define fluid flow passages through the disk between the central opening and the perimeter edge. The fluid flow passages through the disk are adapted to swirl fluid flowing through the disk from the bottom side to the top side around the central opening. The present invention also provides a water treatment vessel that includes one or more distributor plates, a method for manufacturing a composite pressure vessel that includes one or more of the distributor plates and a method for preparing a composite pressure vessel that includes one or more of the distributor plate for use as a water treatment apparatus.

Abstract: A method and apparatus for the removal of at least part of the impurities of bio-diesel fuel, said impurities typically arising from production said purification involving exposure of the ‘raw’ bio-diesel to one or more fragments of plant material. The purification process can be a batch or continuous process.

Abstract: An apparatus for purifying a liquid including: reaction chambers that utilizes an ionization reaction material in turbulence with the liquid, a first fine collective filtration unit, a first laser photolytic light chamber that utilizes ultraviolet light in the 100 to 300 nanometer range to irradiate liquid, a second ultra-fine collective filtration unit, and a pharmaceutical grade granular activated carbon filter unit.

Abstract: The present invention realizes an ion exchange apparatus capable of enhancing the reliability of regeneration operation. Further, the present invention realizes an ion exchange apparatus capable of simplifying the construction of a salt water supply device. The ion exchange apparatus includes a resin bed housing part (2) in which an ion exchange resin bed (5) is housed; a flow passage control valve (3) for switching between a water service operation and a regeneration operation; and a salt water tank (40) for reserving salt water to be used in regeneration, the flow passage control valve (3) being connected to the salt water tank (40) through a salt water supply line (31), in which the salt water supply line (31) is provided with a flow detecting unit (48) for detecting a flow rate in a direction of supplying salt water and a flow rate in a direction of supplying refill water.

Abstract: This invention relates to a novel low operating head polishing sand filter comprising: (a) a plural-layer media bed comprising small, medium and large crushed quartzite; (b) an untreated water inlet system; (c) an underdrain system; (d) a filtered water collection and outlet system; and (e) a backwash water inlet, collection and siphon outlet system.

Abstract: The equipment incorporates a tank that contains a moving bed of sand and inside which there is the device of the invention, which comprises a tubular pumping device associated with a space coaxial with an inlet conduit for the water to be treated and with outlets for said water within the bed of sand, including a sand washer placed in the upper part of the pumping structure, and also an outlet conduit for clean water and an outlet conduit for dirty water. Novelty focuses on the tubular pumping structure, which includes a fluidizing nozzle and also a lateral injection of air, with the interposition of a laminar filtering body.

Abstract: A fluid treatment system that includes at least one treatment module (“pod”) with rigid and impermeable inner and outer surfaces, and an annular center passage which is designed to provide an alternative flow path during the pod backwashing process. At least one chemical treatment media disposed in the interior portion of the pod. A riser extends upwardly through the pod so that the outer surface of the riser and the inner surface of the pod define the annular passage. At least one valve assembly controls the movement of a fluid within the annular passage. The pod is serviced by directing the fluid into the riser and then directing the fluid through the pod, a portion of the fluid flowing through the annular passage.

Abstract: A method and apparatus are provided for a water treatment system that includes both filtration and ultraviolet disinfection elements in a single unit. Various embodiments include a complete treatment system having replaceable filter elements or granular filter media and ultraviolet disinfection within a single vessel. A control valve controls flow through the system in filtering, backwashing, cleaning, and rinsing modes of operation. Other embodiments include couplings that may be adapted to new or existing treatment systems to provide ultraviolet disinfection to a vessel containing replaceable filter elements or granular filter media. The coupling is adapted to receive a control valve assembly that controls flow through the vessel in filtering, backwashing, cleaning, and rinsing modes of operation.

Abstract: A method for treating metal-working fluid comprises reducing a concentration in the metal-working fluid of at least one metal by passing the metal-working fluid through an ion-exchange filter. The at least one metal may comprise cobalt or one or more other metal(s). The ion-exchange filter may include an ion-exchange resin, and the resin may comprise a sulfonated divinyl-benzene-cross-linked polystyrene ion-exchange resin. The metal-working fluid may be recirculated through the ion-exchange filter, from a holding vessel, from a sump or reservoir, or from any other container of the metal-working fluid.

Abstract: The present invention provides a water treatment system, such as a water softener, with a resin tank having a top distributor with a preliminary screen and second screen. The preliminary screen provides added protection by reducing the chance of larger particles from entering the various valves and screens. Prior to the regeneration cycle, an additional back wash and fast rinse cycle are added to rinse sediment to the drain and to clean the preliminary screen.

Abstract: Disclosed is a water softener capable of producing soft water at various temperatures and facilitating the regeneration of an ion exchange resin thereof. The water softener includes a water softening tank in which an internal region containing therein the ion exchange resin is partitioned into a plurality of water softening regions which are individually assigned into a predetermined temperature; a regeneration tank integrated with the water softening tank into a single body and containing the regeneration material of the ion exchange resin; a cold/hot control valve to supply raw water to a selected one of the plurality of water softening regions according to the temperature of the raw water to rapidly supply the soft water at a desired temperature to a user; and a regeneration valve to facilitate the periodic regeneration of the ion exchange resin through a simple manual operation.

Abstract: An apparatus and method for purifying a liquid including: reaction chambers that utilizes KDF 85 or KDF 55 or other media in turbulence with the liquid, a first fine collective filtration unit, a first laser photolytic light chamber that utilizes a laser producing ultraviolet light in the 100 to 300 nanometer range passing through a quartz tube that is surrounded by the liquid, a second ultra-fine collective filtration unit, a pharmaceutical grade granular activated carbon filter unit, and a second laser photolytic light chamber that utilizes a laser producing ultraviolet light in the 100 to 300 nanometer range passing through a quartz tube that is surrounded by the liquid wherein the laser light generator is the same one utilized in the first photolytic light chamber, whereby microbes are killed and collected, aromatic ring structures are eliminated and any particulate matter 0.5 microns or larger are removed from the liquid.

Abstract: Mineral contaminants are removed from water in a system in which water is sprayed into an air head at the top of a tank through a diffuser and withdrawn through a pick-up tube. A solenoid valve operates to allows air from a compressor to flow into the top of the tank through a shuttle valve which is opened by the air pressure. Simultaneously a drain valve connected to the shuttle valve opens a drain, venting water and air from the tank. The shuttle valve, closed by the solenoid valve, closes the air supply line and connecting the shuttle valve to atmosphere, and pressure within the aeration tank can close the shuttle valve, which causes closing of the drain valve. The part of the valve which opens the drain is made responsive to excess pressure within the air tank to open the drain and so acts as a pressure relief valve.

Abstract: An antibacterial member is constituted such that a propolis component is contained in, or adhered to, a water-insoluble base member. This antibacterial member is mixed into a filter member to be disposed in a flow passage in an antibacterial filter. Water in the antibacterial filter receives the antibacterial action from the propolis component when coming in contact with the antibacterial member. Thus, microorganisms in water is extinguished, and generation and propagation of germs, bacteria, algae and the like are suppressed.

Abstract: A device for the deionization of incoming water is disclosed. The device includes a tank and a generally hollow distributor tube in the tank for ingress into and downward movement of unpurified water through the tank. An opening adjacent the bottom of the generally hollow distributor tube and near the bottom of the tank distributes the unpurified water out of the generally hollow distributor tube. A mixed bed of purifying resin is within the tank, and surrounds the generally hollow distributor tube. The unpurified water travels upwardly through the tank where it is deionized to a high purity water by the mixed bed of purifying resin, after egress from the opening. The deionized water passes through a distributor and a filter before leaving the tank through an outlet.

Abstract: The SSF/x slow sand filter for use in treating drinking water for homes or rural villages with features providing simpler on-site assembly, preset maximum flow, easy monitoring of pressure head loss, protection of piping, and a harrowing system for cleaning. The filter employs a novel hydraulic scheme which places most pipe and plumbing within the filter vessel. The filter employs a novel device that combines flow control, pressure measurement, freeze protection, and anti-siphon features. This in combination with a relatively shallow supernatant level provides for consistent reliable operation, easy maintenance, and reasonably long filter runs as deemed very desirable in remote rural locations.

Abstract: A method, system and apparatus for treating water is provided including a treatment mode comprising the steps of drawing said water from a pressurized water source through a controlling device to a treating vessel, the water inlet of said treating vessel being substantially at the top of a treating vessel, contacting said water with pressurized air present at the top of said treating vessel to release substantially all hydrogen sulfide and offensive odors present in the water and to dissolve oxygen in the water which reacts with soluble iron in the water to form ferric oxides, flowing the water through a filter bed of calcite mineral to remove substantially all sediment present in the water and to neutralize the ph of the water and to remove substantially all the ferric oxides from the water, the ferric oxides fastening to the calcite minerals and to already fastened ferric oxides, flowing the water to a final media means and to the outlet of the treating vessel.

Abstract: A water softener system including a hard water flow pipe through which hard water flows, a modular water softener assembly, and a regeneration tank is provided. The modular water softener assembly includes an elongated tube having a first end, a second end, a length extending therebetween, and a predetermined inner volume for storing an amount of water softening particles. The water softener assembly also includes a first end cap coupled to the tube at the first end having a first port in flow communication with the hard water flow pipe and a second port in flow communication with an outlet pipe through which soft water flows. The water softener assembly is supported by the hard water flow pipe and the outlet pipe. The regeneration tank contains a regenerate for regenerating the water softening particles and is in flow communication with the water softener assembly.

Abstract: A device for the deionization of incoming water. The device includes a tank and a generally hollow distributor tube in that tank for ingress into and downward movement of the incoming water through that tank. Slots adjacent the bottom of the generally hollow tube and near the bottom of the tank are provided for distributing the incoming water out of the hollow tube. There is a bed of mixed bed ion exchange resin within the tank. This bed of resin surrounds the generally hollow tube, through which the incoming water travels upwardly. The water is deionized by the ion exchange resin, as it moves upwardly through the resin, after egress from the slots.

Abstract: A method, system and apparatus for treating water is provided including a treatment mode comprising the steps of drawing said water from a pressurized water source through a controlling device to a treating vessel, the water inlet of said treating vessel being substantially at the top of a treating vessel, contacting said water with pressurized air present at the top of said treating vessel to release substantially all hydrogen sulfide and offensive odors present in the water and to dissolve oxygen in the water which reacts with soluble iron in the water to form ferric oxides, flowing the water through a filter bed of calcite mineral to remove substantially all sediment present in the water and to neutralize the ph of the water and to remove substantially all the ferric oxides from the water, the ferric oxides fastening to the calcite minerals and to already fastened ferric oxides, flowing the water to a final media means and to the outlet of the treating vessel.

Abstract: A device for the deionization of incoming water is disclosed. The device includes a tank and a generally hollow distributor tube in the tank for ingress into and downward movement of unpurified water through the tank. An opening adjacent the bottom of the generally hollow distributor tube and near the bottom of the tank distributes the unpurified water out of the generally hollow distributor tube. A mixed bed of purifying resin is within the tank, and surrounds the generally hollow distributor tube. The unpurified water travels upwardly through the tank where it is deionized to a high purity water by the mixed bed of purifying resin, after egress from the opening. The deionized water passes through a distributor and a filter before leaving the tank through an outlet.

Abstract: A separation apparatus, in particular intended for separation of amalgam from water, includes a pre-settling chamber, a distribution chamber and a fine settling zone. The fine settling zone includes a plate package, with a plurality of plates fixed with spacing, forming settling channels. The plates can be machined so that they are provided with a large number of fine bumps and recesses.

Abstract: The present invention provides an apparatus and method for aeration in a filter system. The present invention provides an air injection adaptor for coupling between a filter tank and a valve controller.

Abstract: A filtering device (1), and particularly a filtering device (1), applied to a filter for home water purification is disclosed. The object of this invention is to provide a water filter of a device (1) which improves the efficiency in the water filtration accomplished by ceramic cores (10), thus eliminating the need of employing carbon filled cores or further elements for the filtration (2), and which, in addition, also enables the replacement of the element (1) without the need to replace the core (10). Such object is attained by a filtering device (1), adaptive to a filtering core (10) to be used in a water filter, the core (10) having a tubular projection (14), the device (1) comprising a recipient (3) filled with filtering elements (2), the recipient (3) being associated to a tubular projection (14) and trapping the water previously filtered by the core (10).

Abstract: An apparatus for use in connection with removal of elements, especially exogenous antibodies, from blood or plasma flowing in an extracorporeal blood circulation system of a patient, where said apparatus comprises a container (1). This container is adapted to receive an adsorbent and comprises an inlet (15) and an outlet (16) which are adapted to be connected to an inlet conduit (19) and an outlet conduit (20), respectively, forming part of the blood circulation system. The container (1) comprises an inlet chamber (31), an adsorption chamber (32) adapted to receive the adsorbent, and an outlet chamber (33). These chambers are arranged in sequence when seen in the flow direction of the blood or the plasma through the container (1) and are separated by means of filter units (11, 12) allowing passage of the blood or the plasma. The inlet (15) and the outlet (16) are arranged adjacent one another in connection with a common movable valve means (21).

Abstract: Regeneration of water treatment media is disclosed which includes a water treatment unit having one or more media therein, and which upon initiation of flow of the water, imparts turbulence and abrasion to the treatment medium to automatically cleanse the medium of light solid contaminants, as well as contaminant coatings on the media. This greatly improves the operation of the media and extends its life. In addition, the water treatment unit disclosed may simply be rotated through any one of a number of positions between service, backwash, flush, off, and/or bypass operational modes for further regeneration of the treatment media.

Abstract: A multimedia fluid treatment unit and rotatable valve are disclosed in which a plurality of discreet containers are removably stacked upon each other and contain various different and distinct water treating media. The rotatable valve is rotatable between either of three positions one of which is a service position for routing the water to be treated through the unit for treatment, a second of which is a rinse position for rinsing the media in the unit, and a third of which is a backwash position for backwashing and/or regenerating the media.

Abstract: The invention is directed to purification of liquids, such as drinking water using filters, wherein filtration is effected while the liquid flows upwardly. The invention includes both the method and a device enabling the method to be carried out. The device is constructed to intake impure liquid at the bottom of the filter and initially to effect flow by filling liquid to above the filter outlet near the top, and maintaining flow thereafter by virtue of the presence of a low internal pressure that develops as the liquid passes through the system.

Abstract: A water tank is proposed with a filter cartridge especially for use in automatic vending machines in which the risk of contamination and bed compaction of the filter bed are reduced or avoided. This is accomplished according to the invention by the water inlet opening of filter cartridge being located at the bottom, with a passageway provided for the water to pass through filter cartridge upward and a descending drop line to guide the water to drain of water tank, located at the bottom.

Abstract: A filter assembly for a water purifying apparatus including a plurality of cartridges. Each cartridge includes first and second ends and an interior volume containing a filtering medium. A plurality of end caps are respectively connected with the first ends of the plurality of cartridges and each end cap includes a water inlet and a water outlet. A removable manifold is coupled with the water inlets and water outlets and the manifold includes a pair of auxiliary ports. One auxiliary port directs water from the cartridge assembly to an auxiliary processing device and another auxiliary port directs the water from the auxiliary processing device back to the filter assembly. The water inlets and water outlets extend generally parallel to a longitudinal axis of each cartridge. The cartridge includes an outer tubular member in fluid communication with the water inlet and an inner tubular member in fluid communication with the water outlet.

Abstract: A fluid sanitizer includes a substantially cylindrical cartridge for containing sanitizing media such as a silver bactericide. The sanitizer inserts into an existing filter in the normal filter flow path and permits filtering and backwashing. The cartridge is a full flow design and may either be packed bed or loosely packed to become fluidized under filtering conditions. Sand filters with either top-mounted or side-mounted valves may be retrofitted with the sanitizer with no or minimal modifications.

Abstract: A water filter is packaged in a way that permits longer dwell time and greater volume in a dwell passage of the water filter. In one embodiment the water filter includes an influent passage where a biocide is imparted to the water, a dwell passage where the water remains in contact with the biocide for at least a predetermined duration, and an effluent passage where the biocide is removed from the water. The water filter includes a replaceable cartridge mounted in a pressure vessel. By arranging the dwell passage to include a pan shaped portion in the bottom of the vessel and an axial portion along the extremity of the cartridge, greater volume, greater mixing, and more effective disinfecting result. Another embodiment includes a series of baffles on the exterior surface of the cartridge that create further turbulence for mixing the biocide with the water.

Abstract: Regeneration of water treatment media is disclosed which includes a water treatment unit having one or more media therein, and which upon initiation of flow of the water, imparts turbulence and abrasion to the treatment medium to automatically cleanse the medium of light solid contaminants, as well as contaminant coatings on the media. This greatly improves the operation of the media and extends its life. In addition, the water treatment unit disclosed may simply be rotated through any one of a number of positions between service, backwash, flush, off and/or bypass operational modes for further regeneration of the treatment media.

Abstract: A filtering device for removing contaminants from fluids, comprising a container having an interior chamber with a volume, at least one inlet, at least one outlet and at least one substantially non-granular material adhering outlet filter and at least one type of granular material occupying about 20 percent to about 67 percent of the volume of the container, the granular materials being agitated by the fluid entering the chamber through the inlet and exiting the chamber through the outlet with the outlet filter preventing the granular media from escaping the container, whereby the contaminants being removed from the fluid by the fluid agitating the granular materials and the contaminants are kept within the outlet screen.

Abstract: A tank top pretreatment unit and assembly comprises a treatment unit installed inside a water treatment tank, such as a water softener tank, and in the top of the tank for treating the water either prior to its treatment with the primary treating medium in the tank or following such treatment. The treatment unit includes a plurality of chambers which are configured to contain a finely divided water treatment medium of a different kind than the primary treatment medium. Some of the elements may be arranged in series, but many or all are arranged in parallel flow which reduces the pressure drop of the water across the treatment unit, and the inlet openings to the chambers and outlet openings from the chambers are elevationally spaced from each other and the area of the outlet openings is less than the area of the inlet openings to maximize contact and dwell time in the chambers.

Abstract: A modular water treatment and purification system, suitable for home use, is connected to a water supply and contains a closed fluid treatment circuit extending to a water outlet. The closed fluid circuit flows through a plurality of replaceable water treatment modules each having a specific water treatment function, such as the removal of a particular material from the water by the use of filtration, carbon adsorption, ion exchange or the addition of a chemical to balance the desired water conditions. Preferably the circuit also includes traversing a radiation device, for example an ultra violet light, for the purpose of sanitizing the water.

Abstract: A device for the desalination and conditioning of water, in particular used water from electrical erosion machines, in which two ion exchange columns (2, 3) are connected one behind the other, one of which (2) is filled w cationic exchange resin and the other (3) is filled with anionic exchange resin, the two ion exchange columns (2, 3) being arranged in a common, tightly sealed casing (1), and the connections for the feed line (5) and the discharge line (6) of each column (2, 3) being led out of the casing (1) in a leakproof manner.

Abstract: Regeneration of water treatment media is disclosed which includes a water treatment unit having one or more media therein, and which upon initiation of flow of the water, imparts turbulence and abrasion to the treatment medium to automatically cleanse the medium of light solid contaminants, as well as contaminant coatings on the media. This greatly improves the operation of the media and extends its life. In addition, the water treatment unit disclosed may simply be rotated through any one of a number of positions between service, backwash, flush, off, and/or bypass operational modes for further regeneration of the treatment media.

Abstract: A water filter system having a housing for a plurality of serial-flow connected filter cartridges with distinct filtering characteristic related to the direction of flow of water being filtered. Each filter cartridge has a membrane wrapped activated carbon filter body. One of the filter bodies includes a heavy metal bacteriostat. The cartridges are each releasably retained in a manifold by keyed connectors including rotatable locking rings. Each cartridge having a distinct filtering characteristic includes a keying structure to ensure that the cartridge can only be connected to the manifold for placement in proper serial-flow relationship in the system. The filter system includes a spent filter cartridge indicator. The filter system is particularly suited for countertop placement and connection to a faucet.