https://www.purewaterproducts.com/products/wr011

Superb Wrench, Size #18 Size 18. Fits our Hot Water Washing Machine Filters and “Classic” Pura UV1 units.

https://www.purewaterproducts.com/products/mm018

18 GPD TFC Membrane An 18 gallon-per-day thin film composite (TFC) membrane. 18 GPD

https://www.purewaterproducts.com/products/ta802

Round Residential Brine Tank, Blue, 18" X 33" (For a complete tank kit, see Complete Round Residential Brine Tank Kit, Blue, 18" X 33".) 18" X 33"

https://www.purewaterproducts.com/products/ta803

Round Residential Brine Tank, Blue, 18" X 40" (For a complete tank kit, see Complete Round Residential Brine Tank Kit, Blue, 18" X 40".) 18" X 40"

https://www.purewaterproducts.com/products/bw103

Fleck 2750 Backwashing Filter with 18" X 65" Tank 18" X 65"

https://www.purewaterproducts.com/products/bw283

Fleck 2850 Backwashing Filter with 18" X 65" Tank 18" X 65"

https://www.purewaterproducts.com/products/ta804

Complete Round Residential Brine Tank Kit, Blue, 18" X 33" (For tank only, see Round Residential Brine Tank, Blue, 18" X 33".) 18" X 33"

https://www.purewaterproducts.com/products/ta805

Complete Round Residential Brine Tank Kit, Blue, 18" X 40" (For tank only, see Round Residential Brine Tank, Blue, 18" X 40".) 18" X 40"

https://www.purewaterproducts.com/products/uv915

VIQUA VH410 Ultraviolet Unit, 18 GPM

https://www.purewaterproducts.com/products/uv895

VIQUA VH410-F20 Rack Mounted UV System, 18 gpm

https://www.purewaterproducts.com/viqua-uv

VIQUA VH410 Ultraviolet Unit, 18 GPM VIQUA VH410-F20 Rack Mounted UV System, 18 gpm

https://www.purewaterproducts.com/docs/reverse-osmosis-and-undersink-product-dimensions

Product dimensions of Pure Water Products reverse osmosis and undersink filters.

18" 18" 18"

https://www.purewaterproducts.com/docs/5600-multi-media-filter-media-loading-instructions

The media should fill the tank to approximately 18 inches from the top. You should leave at least 18 inches of “freeboard,” or empty space, at the top of the media bed. Freeboard — at least 18 inches of empty space on top of the final layer.

https://www.purewaterproducts.com/products/fr001

Recommended for 18 gpd membrane.

https://www.purewaterproducts.com/articles/flow-restrictors

A guide to determining the ideal flow restrictor for a reverse osmosis membrane, with charts.

For example, the standard flow restrictor used for an 18 gallon per day membrane is a 200 mlm restrictor Thus, an 18 gpd membrane needs about a 70 gallon per day flow restrictor. 4 times 18 = 72. 18 gpd 18 gpd