this unit http://www.aquariumspecialty.com/vertex-puratek-deluxe-100-gpd-ro-di
plus this unit : http://spectrapure.com/RO-RODI/ADD-ONS/MaxCap-D2-Dual-Stage-DI-System-Add-On-w-SuperDI-Cartridges
Booster pump +fully automated flush on the vertex unit(microprocessor controlled) …recently changed cartridges…
$200