Information on the Rainsoft UF-20 reverse osmosis system can be found here:
http://www.waterfilters.net/Rainsoft...m_p_0-906.html
The first stage of the Rainsoft UF-20 RO system can be replaced by the Pentek EPM-10 carbon water filter. The EPM-10 replacement carbon water filter can be found here:
http://www.waterfilters.net/Pentek/w...ers/EPM-10.htm
The replacement membrane for the second stage of the Rainsoft UF-20 RO system is the Rainsoft TFC-RS9-22 ro membrane. The Rainsoft TFC-RS9-22 replacement ro membrane can be purchased here:
http://www.waterfilters.net/Rainsoft...e_p_0-898.html
The third stage of the Rainsoft UF-20 RO system can be replaced by the Pentek CBC-10 carbon filter. The CBC-10 replacement carbon water filter can be purchased here:
http://www.waterfilters.net/Pentek/w...ers/CBC-10.htm
There is also a fourth, optional, stage of the Rainsoft UF-20 that can be replaced by the Omnipure CL6ROT33-B GAC post filter. The Omnipure CL6ROT33-B replacement granular activated carbon post filter can be purchased here:
http://www.waterfilters.net/Omnipure...r_p_0-754.html