The Truth About Permeate Pump Reverse Osmosis Systems
At US Water Systems, we have been believers in Permeate Pump Reverse Osmosis Systems for over 10 years now. With several thousand permeate pump reverse osmosis systems in the field, we believed we were experts on these types of
reverse osmosis systems. However, over the past year or so, we have become somewhat disillusioned with the permeate pump reverse osmosis system because we have had mixed results, primarily with poor water quality.
: I always try different reverse osmosis systems at my home and after trying the nextRO
for several months, I replaced it with a permeate pump reverse osmosis system (50 gpd membrane). For your information, my TDS (Total Dissolved Solids) are around 540 ppm. After 8+ months, I was really discouraged because my TDS routinely remained at over 100 ppm. If I drained the system on back-to-back days, I could get it down below 50 ppm, but it would rise quickly again.
TDS creep was winning the game. In case you don't know what TDS creep is, it is defined as follows:
"The natural diffusion of TDS ions through the membrane from the feed side to the permeate side when the feed pressure is shut off (i.e., when the tank is full). This effect results in lowered water quality." - A Practical Application Manual for Residential, Point of Use Reverse Osmosis Systems by Robert Slovak
Now, before we go any further, it needs to be understood that a permeate pump reverse osmosis system should do the following:
- A Permeate Pump RO should make water faster than an ordinary RO
- A Permeate Pump RO should make higher quality water than an ordinary RO
- A Permeate Pump RO should waste about 80% less water than any ordinary RO
- A Permeate Pump RO should deliver the highest pressure at the faucet of any RO
Well, my pressure was good. Excellent actually, as I was feeding two ice makers, a kitchen faucet and a humidifier. It makes water very rapidly and I know that it wasted less water, but the water quality was horrible. Additionally, we have several customers who were not thrilled with their water quality, just as I wasn't. What to do....
Everyone told me that the Aquatec 1000 Permeate Pump was the "cat's meow" but the results were less than stellar. After months of fighting this issue, I decided to try the "old Aquatec 500 Series Permeate Pump" which is designed for membranes up to 50 GPD. Not a 75 GPD or a 100 GPD, but just a 50 GPD.
So, I changed the permeate pump ( a 2 minute job). Then I drained my reverse osmosis tank (the TDS was reading 114 ppm).
When I got up the next morning I checked the TDS and it was 18 ppm! From 540 ppm to 18 ppm... not bad.
It has remained below 25 ppm since then and we have made a decision at US Water: We sell a 50 GPD permeate pump with an Aquatec 500 Series Permeate Pump,
not a 1000 Series.
Here's what bothers me: Why can't the engineers at Aquatec (who makes the permeate pump) and Watts (who USED
to make our permeate pump RO system) figure this out?
All 50 GPD Permeate Pump Reverse Osmosis Systems from US Water now have the Aquatec 500... and exceptional water quality.
This is a public service announcement brought to you by The Water Doctor!
Oh... the 500 is also quieter than the 1000... duuuuhhhhhh!