reef-freak
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thanks Jason 2459 for your response. are you talking about the Buckeye for the big savings?
Saddle valves and Low pressure to RODI unit
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jason2459
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Actually all those that provide 1:1 waste to production ratio will help reduce water usage which means less overall water going through prefilters extending their useful life.
With the right membrane any of them that provides over 98% rejection will save on DI.
Buckeye Hydro is the best value for me of all those listed above. I'm not saying the spectrapure systems are inferior or superior in any way. I like spectra pure products too. I love and use several of their peristaltic pumps.
A 1:1 or even 2:1 waste ratio only works in certain applications.
The Spectrapure MaxCap UHE and their new Performers are the exceptions since they use stored DI water to flush and to pickle or store the membrane soaking in when it is idle.
No other RO/DI does this so cutting the waste ratio is risky and can be expensive on membrane and DI replacements unless you have both softened or naturally soft water and much lower than normal tap TDS. If you do not have both of those don't even consider lowering the waste ratio to anything less than 3:1 or you will greatly reduce the life of your RO membrane and your DI resin.
Membranes must be flushed and this is the whole reason for the 3:1-4:1 waste ratio, to continuously flush the membrane while it is operating. Reduce that ratio and the membrane is stewing in a TDS sludge and will not last guaranteed.
Spectrapure sends hardness tester strips or kits with their reduced waste systems so you can adjust the actual waste according to your own unique water conditions. Never assume you can just reduce the waste just because someone sells a supposed one size fits all RO/DI, it's not that easy. It all comes down to cost per treated gallon, yes you can reduce the waste but the trade off is reduced component life which drives the cost of ownership up.
The Spectrapure MaxCap UHE and their new Performers are the exceptions since they use stored DI water to flush and to pickle or store the membrane soaking in when it is idle.
No other RO/DI does this so cutting the waste ratio is risky and can be expensive on membrane and DI replacements unless you have both softened or naturally soft water and much lower than normal tap TDS. If you do not have both of those don't even consider lowering the waste ratio to anything less than 3:1 or you will greatly reduce the life of your RO membrane and your DI resin.
Membranes must be flushed and this is the whole reason for the 3:1-4:1 waste ratio, to continuously flush the membrane while it is operating. Reduce that ratio and the membrane is stewing in a TDS sludge and will not last guaranteed.
Spectrapure sends hardness tester strips or kits with their reduced waste systems so you can adjust the actual waste according to your own unique water conditions. Never assume you can just reduce the waste just because someone sells a supposed one size fits all RO/DI, it's not that easy. It all comes down to cost per treated gallon, yes you can reduce the waste but the trade off is reduced component life which drives the cost of ownership up.
The DI suffers also since the rejection rate goes down when the membrane is not being flushed well while being in use. The TDS builds up and passes through to the permeate.
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jason2459
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Unless the rejection rate is over 98% as it is with the Gapper. Again, I'm not talking at all about taking a standard RO unit with typical 4:1 ratio and 96-98% rejection rates here. Which this thread really isn't about all that but the Gapper thread I linked to could be [emoji4]
This thread was brought up because of my surprise at how much a simple saddle valve could hinder the running pressure of a RODI unit. The Gapper I only mentioned because that's why I ended up switching off the saddle valve. I created the thread just on The Gapper and its features to discuss those.
http://reef2reef.com/threads/the-gapper-400gpd-light-commercial-ro-from-buckeye-hydro.290479/
And I'm glad someone else is hopefully getting some help and figures out a pressure related issue because of this thread.
Say your tap TDS is 200. At a 4:1 waste ratio the TDS surrounding the membrane will be about 20-25% higher than that since it is concentrated. At 1:1 that TDS will be double the tap TDS so 400. At 98% rejection rate the 4:1 will produce a permeate of about 4-5, but at the 1:1 that permeate will rise to 8 or so. The other issue is the gapper membrane will need replacement much sooner since it is not being flushed with DI water and it has no provisions for chemical clean in place like commercial systems have. I agree, Russ has a nice system there but it is not the answer to everything. I will keep my UHE.
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jason2459
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Not sure where you are getting that this thread is about telling people to buy the gapper or that it will solve all the worlds problems? I have stated the gapper is why I changed off the saddle valve as a background for doing this and that the gapper is for me and I tried to link to a thread I started just for the gapper so this thread wouldn't become focused on it or it's features. (which is has...)
I talked to Russ about what my plans where which included changing out my Membrane every 3 years like I currently do preemptively as I don't ever plan to keep testing for chlorine. It should be just fine with that schedule.
IME so far with just over 1:1 ratio I'm getting 98.4% rejection with really cold water. I posted about that in the Gapper thread. FWIW my TDS is just over 300 and it's post water softener. @Buckeye Hydro can give much more detailed answers on how or why the gapper works. I can just give numbers on what I'm getting out of it.
Please by all means keep the Spectrapure it's a great system. Never ever said it wasn't and even stated in this thread and many other threads I like their products. Still don't know where you are getting that I've stated the gapper is the end all be all. It is perfect for me and have stated that and why (also in that other thread).
Russ asked me to look at the Gapper before he brought it to market 4 months ago. He and I talk on occasion and he is familiar with my background and I have helped him in the past. The Gapper is a great product as far as it goes. My goal is the best possible water quality at the lowest cost per gallon treated and it would not be as economical as other systems here in the Southwest since it would require more frequent replacements.
You oversimplified how it works, there is a lot more to the equation when you start changing the waste ratio and osmotic pressure. I'm glad it is working for you and keep posting your results over time, that's what these forums are all about. I need to do an update on my UHE after 8.5 years use myself.
You oversimplified how it works, there is a lot more to the equation when you start changing the waste ratio and osmotic pressure. I'm glad it is working for you and keep posting your results over time, that's what these forums are all about. I need to do an update on my UHE after 8.5 years use myself.
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jason2459
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Yes, over simplification in a thread that it's not on topic about is fairly justifiable. I didn't relate 1:1 as saving on DI only that it reduces water usage and less water going through prefilters. Only Rejection rates did I relate to DI.
