Wednesday, November 13, 2013

Can I Use a Salt-Free Conditioner to Protect My RO Membrane?

How effective is the salt free system at protecting from fouling or scaling of RO membranes?  [My water has] TDS of ~950 and hardness 12 gpg.  Can this be used instead of an anti-scalant injection system to protect RO membranes from premature failure? I really don't want to use a water softener in front of the RO system. I am looking for alternatives if they are not a compromise. Thank you very much!!

Brian D.
St. Louis, MO


PreTreat+ NSF
PreTreat+ Antiscalant
The best way to protect an RO system's membrane from scaling is to use a metering pump to inject an anti-scalant such as PreTreat+ NSF or something similar.  Injecting 2-4 PPM of this non-toxic anti-scalant will be much more effective than a no-salt conditioner.  While the PreTreat+ NSF is a bit pricey, a one 5-gallon pail will typically last for 1-2 years in residential applications, and will dramatically extend the life of your RO membrane.

Stenner 45 MHP w/ 15 gal Tank
Stenner Pump with 15 Gallon Tank
We recommend using a Stenner metering pump and solution tank for the anti-scalant injection, as they are easy to install and use and are very reliable. Stenner pumps also require very little maintenance once set up, and are not prone to losing their prime - a pump “loses its prime” when it becomes dry and full of air or gas bubbles - like other low-cost peristaltic pumps

For more information on salt-free conditioners, check out this short slideshow.  To learn more about RO systems, check out our reverse osmosis FAQ.  

If you have any further questions, e-mail us at, contact us on Facebook, or use our online contact form.  Thanks for the letter, Brian!