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Discussion Starter · #1 ·
So I finally broke down and bought a ro/di unit. The quality of the tap water around here has dropped off abysmally. So I shelled out for a Vertex Puratek 100GPD Deluxe unit, mainly for the low waste (my biggest complaint against RO). However the instructions, which are lacking, say to not use the first 30 minutes of production water and the membrane says 2 hours (before using for drinking water). Does anybody have any experience with this?
 

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Sorry you bought that particular unit but RO membranes are treated with an antimicrobial agent that must be rinsed away before use. Usually 3 to 5 gallons does the trick.
Do not be surprised if you have premature membrane failure, manufacturers and vendors have tried low waste tap water systems for 25+ years and given up on that particular method long long ago. I really hate it when a new overseas vendors pops up with a technology that has been dismissed by other in the business for decades and is prone to failure.
If it were that easy don't you thing vendors like Watts premier, GE, Whirlpool, Koch, Spectrapure, Air Water & Ice, PurelyH2o and others who have been doing water treatment as their main source of income for years would have systems like that available? Talk to them, they all tried it and dismissed it years ago, it doesn't work for long and they depend on customer satisfaction to stay in business for 25+ years. Its a little different with importers, they make their cash then split the scene I suppose.
 

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Discussion Starter · #3 ·
First off thanks for the reply. As far as I understand spectrapure does make low waste units (UHE series). These units look almost identical to the vertex ones with the exception of a second DI and lower waste (1:1 vs 1.5:1). Not trying to argue just trying to understand.
 

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The Spectrapure UHE is a completely different technology. The UHE uses stored DI water to flush the membrane then pickles or stores the membrane in DI water when not in use. That is only one difference, it also includes a 90 GPD RO membrane which has been treated with a special proprietary process proven to increase performance to better than 98% rejection rate guaranteed and to improve GPD production then individually hand tested to ensure its performance which is written right on the membrane and housing along with the testers name and date. Next it uses specially custom blended DI resins in both the MaxCap and SilicaBuster cartridges which again are proven to improve not only performance but also lifespan.

The differences are huge and there is no comparison between them. I own the UHE myself and on only my second MaxCap DI cartridge after 26 months of usage in Phoenix with a tap water TDS over 800 most times. The RO membrane is running at 1:1 now but was ran at 0.67:1 for about the first year to see if it would do it. The RO only rejection rate is still over 99.35% to this day.

The Vertex is basically a pumped RO system with the added benefit of a tap water flushing feature. I would not attempt to run it at anything less than 3:1 waste ratio if your TDS is anywhere near the national average of around 250 or you will end up with a fouled membrane in no time at all. Unfortunately tere are lots of dissatisfied customers on all the reef forums and that is what gives the RO/DI industry a black eye. Vertex should have done their homework before reintroducing something others gave up on years ago. Simply put, it does not work for long as the membrane is not flushed sufficiently and will fail. Again, talk to any of the long time manufacturers and let them tell you about all the lab, bench and beta testing they have gone through over the years, I guarantee you they tried it years ago.
 

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Discussion Starter · #5 ·
Well I guess since I bought it and we'll see how long it lasts. I have read of multiple people with no problems for at least the first year. Maybe I'll get lucky. Also, how does one adjust the waste ratio on an automated unit?
 

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Membrane failures don't happen overnight unless you have high TDS waters. The effects become evident over a period of weeks or months, usually slowed production leading up to elevated TDS levels in the treated water when the membrane starts to rupture.
with good prefilters and carbons and proper flushing a membrane can last as long as 10 years with most in the 3 year range when maintained properly. I would expect 12 to 18 months if its not flushed well and you have much for TDS.
Changing the waste ratio is as easy as changing the flow restrictor or adjusting it if its a needle valve adjustable type. Restrictors are about $5 for a capillary tube type you trim for your exact conditions.
I am sort of anal when it comes to water quality and RO/DI performance so I keep a log book which makes it easy to spot trends and performance problems, when you are just looking at it occasionally its hard to spot changes or problems. I recommend keeping a log and write down the tap water TDS, RO only TDS, RO/DI TDS, incoming pressure, membrane pressure and temperature on a regular basis so you an spot problems early and avoid high cost replacements. A drop in pressure or GPD or an increase in TDS is easy to track that way and can be corrected easily.
 
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