Apec essence 75 gpd ph 6 stage complete filter set is made with high quality filtration components to protect and prolong the lifespan of your reverse osmosis system. Premium quality filter set lasts over 6 months for high performance contaminant removal, while the membrane and post carbon filter last 2-4 years. The 6th stage ph+ inline filter enhance the ph of water and adds food grade quality calcium carbonate into the water. Compatible for apec 75 gpd essence roses-ph75 under the counter reverse osmosis systems. 1St stage: sediment removal 5 micron 10 inch filter -removes dust, particles, and rust. Protects and extends the life of the membrane and system. 2Nd and 3RD stage: carbon block 10 micron 10 inch filter -gets rid of unpleasant chlorine, tastes, odors, cloudiness and colors. Also removes VOCs and other common chemicals from the water. 4th stage: high rejection 75 gpd tfc reverse osmosis membrane. Removes a wide variety of contaminants including arsenic, bacteria, chlorine, lead, fluoride, chromium, radium and more. 5th stage: coconut shell refining carbon 10 inch filter -removes any possible residual taste from the tank. 6th stage: 10 inch high purity ph+ calcium carbonate alkaline inline filters W/quick connect-increases ph level of the water by adding calcium carbonate mineral back into the water about apec for over 17 years, apec has been an industry leading manufacturer who specializes in high performance ro systems. As the original manufacturer, we have dedicated a knowledgeable and sincere team that is committed to providing customer SATISFACTION in hopes to bring many years of enjoyment and good health for you and your family. Apec water does not distribute or sell our products to any 3RD party sellers on Amazon. Please purchase genuine apec water products from Amazon or apec water directly for authenticity.