is removed from by the R/O and the DI
. Basically it is a negatively charged resin that attracts positively chared ions. Once it's full the heavier molecules are attracted and break off the weaker bonds and they are released into your water. PO4
is a weaker bond. Example: your R/O membrane fills up and the next lead particle comes along and sticks to the resin and knocks off a PO4
molecule. The DI
cartrige will also remove anything the R/O membrane left behind. You can have a full R/O membrane and still get a TDS
reading of zero with a new DI
cartridge. However you will quickly use up your DI
and have to replace it often. They are supposed to work as a team. All cartriges should be changed at the same time when the TDS
reading begins to climb.
This info per B. Stone, Indiana State Water Board Member and fellow reefer.