the present invention is a saltwater or freshwater mixing tank and aquarium environmental control system which is designed to exchange used water for pre - conditioned and stabilized water and can be used to quickly drain the main fish tank for easy cleaning and refilling . this invention is designed to connect to existing plumbing both drainage and water supply at the location that the aquarium is installed . secondly , the current invention requires a cabinet that provides access to the components of the aquarium and proper support . the present invention is designed as a complete modular unit that does not allow for various embodiments within the design of the aquarium . instead , all of the necessary aquarium components are designed and assembled to work together when connected to existing plumbing . the present invention is a manual aquarium water changing and water stabilization system . future designs will allow for other tank position setups and aesthetics . as depicted in fig1 the present invention includes ½ inch copper supply lines 1 , for hot and cold water . a valve body 2 , that is bracketed to the left side of the cabinet mixes hot and cold water which exits thru the neck of the valve 3 . as depicted in fig4 the top water change tank 32 , can be filled with water that will empty into the main fish tank 38 , thru piping system ( see fig3 ) that empties from the bottom of the water change tank 32 and exits into the top of the main fish tank 38 . in the case of an overfilling of the tanks , an 1 . 5 inch overflow drain piping system ( see fig2 ) allows for proper overflow drainage for both tanks . as depicted in fig2 the present invention includes an overflow drainage flange 4 that secures a horizontal 2 . 3 inch length of 1 . 5 inch pipe 5 , to the back of the upper part of the top water change tank ( fig4 ). in fig2 , this pipe empties into a vertical 90 ° tee connector 6 , which connects to a vertical segment of pipe that serves both as a connector and vent opening for the overflow drain system . two vertical segments of pipe 7 are connected with a vertical 90 ° tee connector 10 , the top vertical pipe segment is approximately 20 inches long and the bottom vertical pipe segment is approximately 26 inches long . the segments of pipe and the 90 ° tee connector total 47 . 5 inches . a 1 . 5 ″ diameter double threaded bulkhead fitting 8 , is put through the back of the upper part of the main fish tank ( fig4 ) and is connected to a horizontal 2 . 3 inch length of 1 . 5 ″ diameter pipe 9 which connects to the vertical 90 ° tee 10 . the bottom of the 47 . 5 inch vertical overflow pipe segment 7 connects to a horizontal 90 ° tee connector 17 . main fish tank water empties from a drain at the bottom of the main fish tank ( fig4 ). as depicted in fig2 , a 1 . 5 ″ diameter double threaded bulkhead goes through the bottom of the main fish tank and connects to a vertical piece of pipe 12 that contains an inner check valve 13 , to prevent backflow . this vertical drain pipe segment 12 is connected to a vertical primary ball valve 14 with a total length of 4 inches for both items 12 and 14 , that is connected to a 1 . 5 inch elbow 15 , pointing to the back of the aquarium and connects to a horizontal secondary ball valve 16 , which connects to the front of the horizontal tee connector 17 , at the base of the vertical overflow main pipe 7 . a horizontal piece of pipe 18 , connects to the back of the tee connector 17 , which is to be connected to existing plumbing . items 16 , 17 and 18 have an approximate total length of 7 inches . to empty water into from the top water change tank ( fig4 ) into the lower main fish tank ( fig4 ) a ¾ inch pipe system ( see fig3 ) is used . as depicted in fig3 , a drain flange 19 , at the bottom of the top water change tank ( fig4 ) connects and secures a 3 . 5 inch vertical pipe segment 20 , that contains a check valve 21 , to prevent backflow from the lower main fish tank ( fig4 ). in fig3 this vertical pipe segment 20 connects to an elbow 22 , and points towards the back of the aquarium . the elbow 22 connects to a horizontal pipe segment 23 , and a ball valve 24 , that have a combined length of 3 inches . this segment connects to an elbow 25 , and points downward and connects to a vertical nine inch length of pipe 26 . at the bottom of pipe 26 , an elbow 27 , is connected pointing towards the front of the aquarium . this elbow 27 , is connected to a 1 . 5 inch length of horizontal pipe 28 , that goes thru upper part of the back of the main fish tank ( fig4 ). in fig3 , pipe 28 connects to an elbow 29 that points downward and allows water to run over a splash guard 30 , to buffer the entry of water into the bottom main fish tank ( fig4 ). fig4 is a sectional front view of the shelves , tanks , and plumbing in the aquarium . the outer cabinet walls , top , bottom and cabinet supports have been hidden in this view to reveal the interior parts of the aquarium . only the upper shelf 43 , and the lower shelf 45 , are parts of the cabinet . the water change tank 32 , has a top tank wall restraint cap 31 , with two equally spaced 18 . 5 ″× 14 ″ water access cutouts . the tank wall retainer 31 , extends down and around the top of the water change tank 32 , by one inch and has a two inch cross piece to add strength to the top of the tank . on the back wall of the water change tank 32 , two inches down and three inches in from the right side of the tank ( from a front view perspective ) is the center of a 1 . 5 ″ diameter hole 35 , that serves as access for the overflow plumbing into the back of the tank and allows excess water to drain out of the tank . the flat bottom of the water change tank 33 , and a bottom tank wall retainer 34 , goes around the rim of the bottom of the tank raising the tank up off the shelf 43 , by about ¾ &# 39 ; s of an inch to prevent condensation on the bottom of the tank . the shelf that the water change tank rests on is 50 ″× 1 ″× 22 ″ and has an 8 . 7 ″× 5 . 8 ″ cutout 44 , four inches from the right side of the shelf and ¾ &# 39 ; s of an inch from the back of the shelf . this cutout allows space for the water change tank 32 , transfer line ( see fig3 ) that leads into the main fish tank 38 . three inches from the back of the water change tank and five inches from the left side of the water change tank is the center of a ¾ ″ circular hole 36 , that allows the water change tank transfer line to be connected to the bottom of the water change tank via a threaded flange . also , in fig4 , the main fish tank 38 , that has a dimension of 48 ″× 24 ″× 18 ″, rests on a 50 ″× 1 ″× 22 ″ lower shelf 45 , that has a 9 ″× 6 . 5 ″ cutout 46 , that starts two inches from the right side of the lower shelf 45 , and ¾ &# 39 ; s of an inch from the back of the shelf . this cutout allows the main fish tank 38 , overflow plumbing to go through the shelf 45 , and attach to the main fish tank waste line ( see fig2 ). the main fish tank 38 has a top tank wall restraint cap 37 , with two equally spaced 20 ″× 16 ″ water access cutouts . the tank wall retainer 37 extends down and around the top of the main fish tank 38 , by one inch and has a four inch cross piece to add strength to the top of the tank . on the back wall of the main fish tank 38 , two inches down and seven inches in from the right side of the tank ( from a front view perspective ) is the center of a 1 . 5 ″ diameter hole 41 , that serves as access for the overflow plumbing into the back of the tank and allows excess water to drain out of the tank . the flat bottom of the main fish tank 39 , and a bottom tank wall retainer 40 , goes around the rim of the bottom of the tank raising the tank up off the shelf 45 , by about ¾ &# 39 ; s of an inch to prevent condensation on the bottom of the tank . in the bottom of the main fish tank 39 , there is a 1 . 5 ″ circular hole 42 , seven inches to the left of the right side of the tank that allows the main fish tank 38 , waste line ( see fig2 ) to enter into the bottom of the main fish tank 38 . this allows for quick and easy draining of the main fish tank 38 . fig5 shows a complete wire - frame view of the aquarium water changing and stabilization system from a perspective to the left and slightly above the front of the aquarium . fig5 &# 39 ; s numbered items point out the components of the aquarium cabinet . the cabinet is made primarily of a wood product . all shelves and wall sections of the cabinet are doweled together for support . the top of the cabinet 47 , has a dimension of 50 ″× 22 ″× 1 ″ as do all the shelves of the cabinet . the bottom of the cabinet 57 , has a slightly larger dimension of 52 ″× 1 ″× 23 ″ for additional stability . the upper left and right cabinet side panels 48 , have a dimension of 22 ″× 14 ″× 1 ″, are doweled into the top of the cabinet 47 , and the upper shelf ( fig4 ). two 24 ″× 15 ″× 0 . 3 ″ left and right upper cabinet doors 49 , provide access to the water change tank cabinet area . between and behind the upper front cabinet doors 49 , is a 3 ″× 14 . 5 ″× 1 ″ center upper front cabinet door support and stop 63 . all cabinet doors use appropriately placed hidden european hinges and have appropriately placed cabinet door handles . on the front of the cabinet and doweled into the bottom of the upper cabinet shelf ( fig4 ), is a 48 . 25 ″× 2 . 6 ″× 1 ″ wood product panel 51 . also , below the upper cabinet shelf ( fig4 ), are a left and right mid cabinet side panels 54 , that have a dimension of 22 ″× 35 . 5 ″× 1 ″ and are doweled into the upper cabinet shelf ( fig4 ) and lower cabinet shelf ( fig4 ). each of these left and right mid cabinet side panels 54 , have two 7 ″× 6 ″× 1 ″ cutouts who &# 39 ; s both upper right hand corners begin at 1 . 8 ″ down from the top of the mid cabinet side panel 54 , and three inches and 12 and a half inches respectfully from the right side of the mid cabinet side panel 54 . these cutouts provide access to each side of the main fish tank cabinet area . each of these mid cabinet side panel cutouts are covered with relatively small 8 ″× 7 ″× 0 . 3 ″ cabinet doors 50 , that use appropriately placed hidden european hinges and cabinet door handles . approximately ¼ ″ below the front cabinet panel 51 , is a swing up front access panel 53 , that has a dimension of 48 . 6 ″× 10 . 8 ″× 0 . 3 ″ and is connected to the mid cabinet side panels 54 , with metal pins 52 , that allow this front access panel 53 , to swing up and provide access to the front of the main fish tank . when this panel 53 , is in the down position , it provides a pleasing aesthetic look to the front of the aquarium cabinet by blocking the view into the interior plumbing and open back of the aquarium . in fig5 , at rear of the mid cabinet section is a left and right mid section “ l ” strut 62 . each of these struts 62 consists of two pieces of wood product , 3 ″× 35 . 5 ″× 1 ″ and 5 ″× 35 . 5 ″× 1 ″ that are doweled and glued together at right angles for strength . the 3 ″× 35 . 5 ″× 1 ″ side of these struts are attached to the interior wall of the mid cabinet side panels 54 , with at least four appropriately placed # 6 gauge wood screws . the lower portion of the aquarium cabinet is designed to allow room 64 , for normal aquarium filtration system hardware . at rear of the lower cabinet section is another set of left and right lower section “ l ” struts 60 . each of these struts 60 consists of two pieces of wood product , 3 ″× 26 ″× 1 ″ and 5 ″× 26 ″× 1 ″ that are doweled and glued together at right angles for strength . the 3 ″× 26 ″× 1 ″ side of these lower section “ l ” struts 60 , are attached to the interior wall of the lower left and right side cabinet side panels 55 , with at least four appropriately placed # 6 gauge wood screws . these lower cabinet side panels 55 , have a dimension of 22 ″× 26 ″× 1 ″ and are doweled into the lower cabinet shelf ( fig4 ) and the cabinet bottom 57 . on all of the back - facing five inch wide piece of “ l ” struts in the mid and lower cabinet sections 62 & amp ; 60 , that are flush with the backend of the aquarium cabinet side panels and shelves , there are 0 . 5 ″× 0 . 5 ″× 1 ″ bolt holes 61 , that allow for 7 / 16 ″ diameter bolts or # 30 gauge self anchoring wood screws to be attached through the back of the aquarium cabinet to the building wall where the aquarium is located . the “ l ” strut bolt holes are located four inches from the top and bottom of the struts and are centered in the back - facing five inch wide piece of the “ l ” strut . these bolts ensure a secure and stable aquarium that will not tip over or sway when properly bolted to the building wall behind the aquarium cabinet . on the front side of the lower part of the aquarium cabinet are two slot vented 24 ″× 26 ″× 0 . 3 ″ left and right lower cabinet filtration system access doors 56 . there are eight equally spaced 23 ″× 0 . 45 ″× 0 . 3 ″ slots 65 , that start at about eighteen inches down and are centered on each lower cabinet door . these front lower cabinet doors are attached to the cabinet by appropriately placed hidden european hinges . appropriately placed cabinet door handles must be on the all cabinet doors for easy opening . between and behind the lower front cabinet doors 56 , is a 6 ″× 26 ″× 1 ″ center lower front cabinet door support and stop 58 . fig6 is a sectional right side view of the aquarium plumbing only that allows conditioned and stabilized water from the water change tank ( fig4 ) to flow into the lower main fish tank ( fig4 ). this section of plumbing starts with a ¾ ″ double threaded bulkhead fitting 19 , that is inserted down into the plumbing access hole located on the bottom of the water change tank ( see fig4 ). this bulkhead 19 , is connected to one of two ¾ ″ diameter segments of vertical pipe 20 which includes a ¾ ″ check valve 21 in the middle . the total length of segments 19 and 20 is 3 . 5 inches . at the bottom of the lower pipe segment 20 , is a ¾ ″ elbow 22 that points towards the back of the aquarium at a 90 ° angle and is attached to horizontal segments of ¾ ″ pipe 23 that has a ¾ ″ ball valve socket 24 , in the middle . segments 23 and 24 have a total length of three inches . attached to the end of the back portion of segments 23 and 24 is another ¾ ″ elbow that points 90 ° downward and is attached to a nine inch vertical segment of ¾ ″ pipe 26 . the bottom end of this nine inch vertical segment of pipe 26 , is attached to a ¾ ″ elbow 27 , that points towards the front of the aquarium at a 90 ° angle and is attached to a horizontal 1 . 5 ″ length of ¾ ″ diameter pipe 28 . at the front end of this horizontal segment of pipe 28 , is a ¾ ″ elbow 29 , that points downward at a 90 ° angle and directs the water flowing out of this plumbing system onto a splash guard 30 , to prevent splashing within the main fish tank when this plumbing is in use . the splash guard 30 , is attached to the back main fish tank wall centered ½ ″ below the elbow 29 .