# RO water in line Before or After Softener?



## epicfish

Softener -> RO -> DI.


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## sunfire99

epicfish said:


> Softener -> RO -> DI.


Hmmmmmm. What is the benefit of softener first? I connected mine to hard water, only because it was easy to plumb to an existing hose valve in my garage. I get TDS of ~4 with a tired membrane. Would it improve, or run faster post softener? Sorry, not trying to hijack the thread. It never even occured to me to think about before or after the softener and it's been installed for 3 years or more.


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## epicfish

sunfire99 said:


> Hmmmmmm. What is the benefit of softener first? I connected mine to hard water, only because it was easy to plumb to an existing hose valve in my garage. I get TDS of ~4 with a tired membrane. Would it improve, or run faster post softener? Sorry, not trying to hijack the thread. It never even occured to me to think about before or after the softener and it's been installed for 3 years or more.


You softener membranes can 'purify' more gallons of water per unit price than the RO membranes and DI resin. It's more cost effective. 

For example, your RO membranes may last 5,000 gallons with a TDS of 100 after your water softener versus 1,000 gallons at a TDS of 500 without a water softener.


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## sunfire99

epicfish said:


> You softener membranes can 'purify' more gallons of water per unit price than the RO membranes and DI resin. It's more cost effective.
> 
> For example, your RO membranes may last 5,000 gallons with a TDS of 100 after your water softener versus 1,000 gallons at a TDS of 500 without a water softener.


Makes a lot of sense. Mr Obvious here just missed it.:icon_roll Thanks for the info.


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## Burks

sunfire99 said:


> Makes a lot of sense. Mr Obvious here just missed it.:icon_roll Thanks for the info.


You wouldn't believe how many times that question gets asked! You are not alone my friend.

And yes, I have asked it before as well. :icon_redf


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## wkndracer

Softener then R O but different reasoning explained to me. 
My Kinetico whole house conditioner uses salt regeneration and is primarily Iron removing. The ion exchange resin canisters strip / exchange sodium ions and in the process filter to 5 microns.
The resulting contaminants at my R O filter are more easily flushed off making the membrane last longer. What ever the scientific explanation behind it my 50gpd system produces over 100gpd product water. Also its produced over 1200 gallons and still registers .01 TDS to the holding tank.


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## metageologist

correct me if i wrong 

but doesn't a water softener just exchange Ca ions for Mg ions which results in the allusion of softer water and makes soap function better. This does not seem to actioly reduce TDS to me it just removes the heavier ions. i believe this was the explanation i got when i was considering building a water softener for my tank. this leads me to believe that whether you place the RO before or after the softener would make little to no difference


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## sunfire99

metageologist said:


> correct me if i wrong
> 
> but doesn't a water softener just exchange Ca ions for Mg ions which results in the allusion of softer water and makes soap function better. This does not seem to actioly reduce TDS to me it just removes the heavier ions. i believe this was the explanation i got when i was considering building a water softener for my tank. this leads me to believe that whether you place the RO before or after the softener would make little to no difference


I'm not sure I can say if it's wrong but I can and have measured TDS pre and post softener. ALmost 500 before the softener and 150 after. Does that mean they are really removed, or just harder to measure? I don't know much more than what the little TDS meter tells me, but I've read similar to what you stated here. It may be dependent on what type of softener is involved. Mine is mostly aimed at iron also, and uses salt regeneration. I'm actually in process of ordering a new membrane from Air water and ice. They sell an inline "softener" to remove some of the solids prior to reaching the RO filter. Would that thing actually help? Plumbing into my soft water means cutting hard copper, sweating in a valve, etc, and I just suck at plumbing.:redface:


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## wkndracer

*Well water readings*
Ph 7.2
kh 196.9 ppm
gh 179 ppm
phosphate 1.0
iron >1.0 (off the scale deep purple nearly black) Hagen Nurtafin test kit.
Nitrate, Nitrite, Ammonia 0.0
*After the Kinetico system*
Ph 7.0
kh 196.9
gh 35.8
phosphate .75
iron 0 < .1 ppm
Nitrate, Nitrite, Ammonia 0.0


Whether or not the house water 'softener' is a true reading of TDS or an allusion of softer water due to ion exchange I really am not qualified to say. The above posted results were obtained with the same test kits and reading are different. That said using this water I could not grow plants and fish had ongoing issues.
Since adding the R O post treatment I no longer am known at the LFS as 'The fish killer'


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## bannh

TDS is tricky, it only measures molecules with an ionic charge. Not everything has a charge. Without a home water softening system I don't have the experience to comment, it would just be guessing. But... I would try the way wkndracer does it. Seems most logical to me.


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## metageologist

thanks for the info didn't mean to hijack the tread i will see if i can run this by our water lab and get a definitive answer. 

i do plan to plum a high flow RO system beneath my tank and into the filter to do my water top offs and changes


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## wkndracer

metageologist said:


> thanks for the info didn't mean to hijack the tread *i will see if i can run this by our water lab and get a definitive answer. *
> 
> i do plan to plum a high flow RO system beneath my tank and into the filter to do my water top offs and changes


You have a good plan of action. :thumbsup: I did the same thing including taking them samples of both pre and post filtered. The plant water lab is geared to Boiler Chemistry and most of their treatments are resin exchange.


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## metageologist

ya im hoping them can give me a difinitive answer on the practicality of a water softner. before the RO system.


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## wkndracer

metageologist said:


> ya im hoping them can give me a definitive answer on the practicality of a water softener. before the R O system.


Not to hijack the OP's thread here but all would like to know I'm sure.
Please do post their recommendations. I've subscribed to this thread.
Thanx in advance.


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## mountaindew

As per the manual for my Spectra Pure Ro/di System!
"For hard water supplies, SpectraPure® recommends the use of a Water Softener ahead of the Reverse Osmosis System for efficient water purification production and operation, water saving and longer life of the membrane. The Water Softener will replace the hardness (mineral, calcium and magnesium) in the water with sodium. This prevents mineral-scale buildup on the RO membrane."
FYI!
MD


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## wkndracer

Hello mountaindew and welcome to the choir! I confirmed this information regarding series configuration prior to building my system. This topic is like that of CO2 injection and whether to place the reactor on the inlet rather than filter discharge. Sometimes people have to reinvent the wheel themselves to accept the best course of action. Sometimes though questions do lead to better answers.

http://www.plantedtank.net/forums/members/metageologist.html


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## metageologist

well after talking to the water lab they said the same thing as mountaindew. if you want the membrane to last longer place it after the water softener if you like buying membranes place it before the water softener. 

so to conclude place it after the water softener.


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## wkndracer

metageologist said:


> well after talking to the water lab *they said the same thing as mountaindew*. if you want the membrane to last longer place it after the water softener if you like buying membranes place it before the water softener.
> 
> so to conclude place it after the water softener.


And the same thing as epicfish and yours truly (just to kick the dead horse and see if he'd run again)


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## metageologist

wkndracer said:


> (just to kick the dead horse and see if he'd run again)


well no running but a slow trot


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## sunfire99

I guess I'll be cutting into my plumbing this week now. I'm on vacation, so at least I have the time to mess with it. I honestly never thought about pre or post softener. Damn, I HATE plumbing!!:icon_cry: I hate paying $50 for a replacement membrane more often even more than plumbing though.


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## wkndracer

sunfire99 said:


> I guess I'll be cutting into my plumbing this week now. I'm on vacation, so at least I have the time to mess with it. I honestly never thought about pre or post softener. Damn, I HATE plumbing!!:icon_cry: I hate paying $50 for a replacement membrane more often even more than plumbing though.


Research based on a history of no luck at all is the only thing that ever saves me from rework.

_Sharkbite_ by cash acme is sold at home depot among other places and takes some of the _bite_ out of plumbing / replumbing.

Quote:
Originally Posted by *wkndracer*  
_(just to kick the dead horse and see if he'd run again)_

well no running but a slow trot

metagoelgist, sorry but just couldn't resist earlier after going through it a couple times before. No harm intended (humor), hopefully no foul taken.


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## metageologist

wkndracer said:


> metagoelgist, sorry but just couldn't resist earlier after going through it a couple times before. No harm intended (humor), hopefully no foul taken.


no harm or foul. humor is always appreciated just read my sig i have other geology saying but probably only ammusing to geologists


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