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#26
AZDesertRat

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Move your IN probe to the tap water side for a few minutes and see what your tap water TDS is. This is a critical piece of information needed to calculate the RO rejection rate or removal efficiency which tells you if the membrane is doing what it should be or if you are relying more heavily on expensive DI replacements.
This is one raseon I dislike inline meters, they are limited to two places, usually post RO and post DI and to troubleshoot a RO/DI system you need three readings not two. With a handheld you can test all three plus your ATO storage, the LFS, you buddies, bottled water, etc.

You will see elevated TDS when you first start making water due to the TDS creep in the membrane. When you shut a RO off, the untreated tap water osmoses or migrates to the treated side of the membrane and raises the TDS contained in the housing. It takes a bit to get rid of that initial water every time you start it back up. So called flush valves DO NOT take care of this since they are flushing the waste side and not the treated side of the membrane as many mistakenly believe.
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#27
GiantBen

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Move your IN probe to the tap water side for a few minutes and see what your tap water TDS is. This is a critical piece of information needed to calculate the RO rejection rate or removal efficiency which tells you if the membrane is doing what it should be or if you are relying more heavily on expensive DI replacements.
This is one raseon I dislike inline meters, they are limited to two places, usually post RO and post DI and to troubleshoot a RO/DI system you need three readings not two. With a handheld you can test all three plus your ATO storage, the LFS, you buddies, bottled water, etc.

You will see elevated TDS when you first start making water due to the TDS creep in the membrane. When you shut a RO off, the untreated tap water osmoses or migrates to the treated side of the membrane and raises the TDS contained in the housing. It takes a bit to get rid of that initial water every time you start it back up. So called flush valves DO NOT take care of this since they are flushing the waste side and not the treated side of the membrane as many mistakenly believe.

Final questions (maybe) :


Wold yourecommend getting the high capacity cartrige (DI-SB-10HC), or would the standard one be enough. I'm wondering if the HC is more for someone who is making more RO than me. I probably make 90 gallons/month.

Also, if I buy a replacment memberane now (MEM-0090), can I just store it, or does it expire? I don't mind buying it now to save on shipping in case I need it.

I plan to but a TDS3 meter so that I can evaluate the performance of my system better.

Thanks!

#28
C.I._Reefer

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Final questions (maybe) :


Wold yourecommend getting the high capacity cartrige (DI-SB-10HC), or would the standard one be enough. I'm wondering if the HC is more for someone who is making more RO than me. I probably make 90 gallons/month.

Also, if I buy a replacment memberane now (MEM-0090), can I just store it, or does it expire? I don't mind buying it now to save on shipping in case I need it.

I plan to but a TDS3 meter so that I can evaluate the performance of my system better.

Thanks!


I think membranes only last 6 months or a year, and that is kept moist in the fridge I think. If you properly maintain your system, your membrane should last MUCH longer than that. I wouldn't. I would only stock up on pre-filters, and MAYBE DI, but DI has a shelf life also.

#29
AZDesertRat

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Spectrapure is different from other vendors in that they specially treat then test all their membranes and pack them in mylar foil bags wet. They need to stay wet so I would not buy one much ahead of time. Normal membranes are preserved, dry and untested so can store indefinitely but you get what you get.

I have not tried the new Super cartridges yet myself but I imagine they are more than worth the few $$ difference. I get a year out of a MaxCap and 3 years out of a SilicaBuster so can only imagine what the new ones will do. I plan to try them at my next replacement but that is still close to 6 months away. They came out with the Super versions a week or two after my last replacement.
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#30
GiantBen

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Got my new cartridges and hand held TDS meter (TDS3) today. Measured the water in my Ro trash can (which is almost empty, expecting to see some TDS and.....000. Measured tap water as a double check and.....176. Can RO/DI have phosphates in it, but have 0 TDS? Every time I do a water change, my cyano seems to be a little worse. I was expecting some TDS in my RO/DI or some phos in my newly mixed salt water, but neither test has ever revealed anything.

EDIT: It's odd that the handheld read zero, since last time I made RO, the output on the dual inline read 001.

Edited by GiantBen, 12 April 2012 - 07:34 PM.


#31
AZDesertRat

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Inlines are not accurate, they are not temperature compensated.
You can have traces, extremely small amounts of phosphates, and they may not register well on a TDS meter since they are weakly ionized but not enough to be concerned about. If your RO/DI is functioning correctly and you use high quality, fresh DI resin you will not have phosphates.
16G Bowfront Nanoreef. 100G SPS dominated reef.

#32
GiantBen

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Inlines are not accurate, they are not temperature compensated.
You can have traces, extremely small amounts of phosphates, and they may not register well on a TDS meter since they are weakly ionized but not enough to be concerned about. If your RO/DI is functioning correctly and you use high quality, fresh DI resin you will not have phosphates.

Sounds like I have to blame something else for my cyano :P

BTW: Thanks for always being so good about answering questions AZ (and everyone else too). You were a big help when I first got my Spectrapure unit, and continue to be.

Edited by GiantBen, 12 April 2012 - 07:50 PM.