Osmonics was purchased by GE a few years back. We still carry the full Osmonics sediment filter line and have found them to be some of the best sediment filters on the market.
I will take you through the line which goes from Puretrex Hytrex - Selex - Flotrex - Memtrex.

The Puretrex is an economical filter that is great for prefiltration on reverse osmosis systems, under sink drinking water systems and other low flow applications. Puretrex is not recommended for whole house applications. The particle retention is not good at higher flow rates.

The Hytrex is a step of from the Purtrex in two ways; higher flow rates and better particle retention. This is a great filter for whole house systems and industrial applications.

The Selex is a high end filter for home systems and entry level for laboratory and high purity water applications. The Selex is available in a 1 micron absolute which we have found to have significantly better removal of smaller particles than either the Purtrex or the Hytrex.

The Flotrex is often used as prefiltration in reverse osmosis systems that are in a food or beverage plant or as the second to last step in a bottle water process. You would run Flotrex, then ozone, or Flotrex then Memtrex. Flotrex filters are also use as prefiltration in laboratory, pharmaceutical and other high purity applications.

Memtrex is for final filtration. If you use a memtrex filter without prefiltration it will plug very quickly. Memtrex is the top of the line in build quality, materials offered and particle retention. It is used for final filtration of food and beverage products, bio-tech, pharmaceutical production, bottled water and other applications that require 5 log reduction capabilities.