Systems and methods for water filtration

Abstract

A water filtration systems may comprise an under the sink RO water filtration system that is plumed into a building's water supply. For example; the water filtration systems may include an RO device at least partially installed underneath a sink, with the tap water connection plumbed directly to the sink cold water supply line, and a waste water drain line connected directly to the sink drain, such as the p-trap.

1 . A reverse osmosis water treatment system, comprising:
 a source of water;   a water tank comprising a first inlet, a second inlet, a first outlet, and a second outlet, wherein the first inlet of the water tank is in fluid communication with the source of water;   a filter system comprising an inlet, a first outlet, and a second outlet, wherein the inlet of the filtration system is in fluid communication with the first outlet of the water tank, wherein the first outlet of the filter system is in fluid communication with the second inlet of the water tank, wherein the first outlet of the filter system supplies waste water to the water tank, and wherein the water tank comprises a mixture of water from the source of water and waste water from the filter system;   a filtered water tank comprising an inlet and an outlet, wherein the inlet of the filtered water tank is in fluid communication with the second outlet of the filter system, wherein the second outlet of the filter system supplies filtered water to the filtered water tank, wherein the outlet of the filtered water tank is in fluid communication with a faucet; and wherein the outlet of the filtered water tank supplies the filtered water to the faucet;   a first pump disposed in fluid communication between the water tank and the filter system; and   a second pump disposed in fluid communication between the water tank and a drain, wherein the second outlet of the water tank is in fluid communication with the second pump, and wherein the second pump supplies a portion of the water from the water tank to the drain.   
     
     
         2 . The system of  claim 1 , wherein the filter system further comprises:
 a first filter and a second filter;   wherein the first filter is configured and disposed to receive water from the inlet of the filter system and to filter and deliver first filtered water to the second filter; and   wherein the second filter is configured and disposed to receive the first filtered water from the first filter, to deliver a first portion of the first filtered water to the first outlet of the filter system, the first portion of the first filtered water being the waste water that is delivered back to the water tank, and to filter and deliver a second portion of the first filtered water, the second portion of the first filtered water being the filtered water.   
     
     
         3 . The system of  claim 2 , wherein the filter system further comprises a third filter, wherein the third filter is configured and disposed to receive the filtered water from the second filter and to further filter and deliver the filtered water to the second outlet of the filter system. 
     
     
         4 . The system of  claim 3 , wherein:
 the first filter comprises a sediment filter, a carbon filter, a KDF filter, or a combination thereof;   the second filter comprises a reverse osmosis membrane; and   the third filter comprises a carbon filter, an ion exchange filter, a remineralization element, or a combination thereof.   
     
     
         5 . The system of  claim 3 , wherein:
 100% of the water that enters the first filter passes to the second filter;   less than 100% of the water that enters the second filter passes to the third filter; and   100% of the water that enters the third filter passes to the filtered water tank.   
     
     
         6 . A reverse osmosis water treatment system, comprising:
 a source of water;   a water tank comprising a first inlet, a second inlet, a first outlet, and a second outlet, wherein the first inlet of the water tank is in fluid communication with the source of water;   a filter system comprising an inlet, a first outlet, and a second outlet, wherein the inlet of the filtration system is in fluid communication with the first outlet of the water tank, wherein the first outlet of the filter system is in fluid communication with the second inlet of the water tank, wherein the first outlet of the filter system supplies waste water to the water tank, and wherein the water tank comprises a mixture of water from the source of water and waste water from the filter system;   a first pump disposed in fluid communication between the water tank and the filter system; and   a second pump disposed in fluid communication between the water tank and a drain, wherein the second outlet of the water tank is in fluid communication with the second pump, and wherein the second pump supplies a portion of the water from the water tank to the drain.