The problem is in deed the ...

Published March 24, 2017 08:03 by Jens Potreck, Pentair X-Flow - R&D Manager Membranes

The problem is in deed the colloidal silica, which will always pass a coagulation step. This fraction can be removed by a very strong, high flux silica removal membranes from PEntair X-Flow. The membrane has a MWCO of 10 kDa.

Please check the website: http://xflow.pentair.com/en/products/hfs60