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twichstile

Coralife RO/DI

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It WAS for the longest time discarding at 4:1. Now the discard rate is negative: about 0.5 discard to 1 production. TDS is still 0ppm.

Just wondering if its time to change stage 1 and 2...or maybe even 3 aswell. Please help.

Dave

Edited by twichstile

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Its time to replace your flow restrictor! Discontiunue use of the system until you get more waste flow or your membrane is trashed.

Change the prefilter and carbon every 6 months and disinfect the system at that time. Replace the DI cartridge or resin when your TDS is anything above 1 and replace the RO membrane when either your production drops drastically or goes up drastically accompanied by high TDS in the effluent.

 

Check your flow restrictor or make sure you do not have a kink or obstruction in the waste line. Time your GPD on the good side and make sure its still wher it should be, you may have a ruptured or damaged membrane allowing untreated water to pass which limits waste flow.

Edited by AZDesertRat

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Thanks AZDesertRat! You have saved me before, not that I would expect you to remember, but it sounds like a BIG "OOPSIE DAISY!!"

 

It is a 50gpd 4 stage

I have discontinued use.

I DO NOT know what a flow restrictor is... The lines are not kinked, they are all curved gently.

I use approx 10 gallons per week, and sometimes just run it for 5-20mins to keep the membrane wet.

I am prepared to do whatever cleaning/changing I need to do to protect that $100 membrane(if it isnt already damaged ofcourse)

 

It hasnt been quite 6 months yet for new 1 and 2 and 3...

 

So has my DI taken a beating then and my membrane is done?

 

 

Quick questions:

Does everyone have problems with Coralife RO/DI?

Is there a refillable cartrige for the DI other than the Coralife NON-refillable model?

 

Thanks,

Dave

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The flow restrictor is on the waste line. I believe on the Coralife units its integral to the 90 degree elbow that connects the membrane housing and 1/4" waste line. If not it will either be inside the waste line in the form of a capillary tube that looks like a piece of spaghetti with a small flange on one end or it will be a fatter plastic piece about 2.5 to 3" long with something like 500m/L printed or stamped on it. Disconnect the waste line then unscrew the elbow and I'll bet its inside there.

I would replace it with a standard John Guest x male iron pipe thread elbow and a capillary tube type restrictor which wil give you better control of the waste and longer membrane life. You can get both from places like Spectrapure or Buckeye Field Supply for maybe $10 total.

 

You might try cleaning yours first once you see what condition its in then reinstall it and time the waste flow.

 

Before spending much money lets do a little troubleshooting first:

If you can get the old restrictor and elbow off, screw another fitting into the housing and attach the tube to it, it an be a straight or 90 degree fitting, it does not matter. If you don't have an extra fitting they are like $3 at Lowes or HD and while you are there pick up a 1/4" John Guest ball valve for maybe $4 to act as a temporary flow restrictor.

Once you attach the waste line to the membrane housing attach the ball valve to the open end and start making water. Adjust the ball valve down so you are getting approximately 4:1 waste ratio and let it run this way for several minutes. Now take TDS readings from your tap water, RO only water before the DI and final RO/DI water. These readings will tell you the condition of your membrane and DI cartridge. If the membrane is OK you should be seeing a 96-98% removal efficiency with the RO only. If the DI is good that TDS should be near 0 but at least lower than the RO only, if its the same or higher the DI is bad.

 

Take a look at the sales flyer here, they have refillable DI cartridges on sale and you can get the other parts you may need too at the same time:

http://www.spectrapure.com/email/customer-...eciation.html#1

 

As you can see membranes are also on a heck of a sale if you end up needing one.

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Wow they are on sale!! I may buy one anyhow!!

Thanks so much DesertRat, I will perform these tasks tomorrow and get a diognosis and get back here :)

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I first cleaned the flow restrictor just to see if any difference and the discard rate has increased, its 3:1 now.

Is 3:1 going to harm anything? I bought the ball valve, I think I will go ahead and use the ball valve until i can ge ta new flow resrtictor.

 

 

 

tap water is 324ppm

after membrane, before DI is 20-21ppm

final production is 0ppm

Edited by twichstile

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You are at about 93.5% rejection which is a little lower than the desirable 96-98%. What you will find is if you make much water the cost of DI replacements could be cut in half or more by installing a new membrane getting you back to the 98% level.

3:1 is not bad but 4:1 would be better with a tap water TDS over 250.

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I just replaced all of the filters just a couple months ago. I have only made about 30-40 gallons on these new filters, the filters are probably 3-4 months old. Im just curious what is causing my membranes to get damaged prematurely, this is my second membrane in a year.

 

A few questions if you dont mind,

1. Does turning the water on/off quickly or slowly matter? (its hooked up to a utility sink in the garage)

 

2. Does letting the unit sit for a week hurt it?

 

3. Can the ball valve be a permanent setup?

3b. Would adjusting the flow up to 5:1 help?

 

Thanks so much desertrat, i really appreciate your help

- Dave

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High quality replacement filters make a big difference in membrane life. Many readily available replacements are high micron nominal rated filters about as effective as a screen door. I spend the extra few $$ and buy prefilters in the 0.5 or even 0.2 micron range, the reason is if it never gets to the membrane to begin with it does not have to work hard at removing it. My membranes last well over 3 years in tap water that runs over 800 TDS for this reason. Same with the carbon block, I only use a 0.5 or 0.6 micron Chlorine Guzzler. High micron rated carbons or granular activated carbons are bad news as they have a very limited chlorine capacity, often as little as 300 total gallons, thats 240 waste gallons and only 60 treated gallons at 4:1.

The difference between absolute rated filters and nominal rated filters is important. Absolute means 99.9% of everything including and larger than its rated micron size is removed by the filter, not many supply these because they cost a little more. Nominal means only 85% of everything larger than the micron size has to be removed. Some off brands don't even have a rating and are not ANSI/NSF aproved meaning they are not tested or certified as safe fro drinking water use in the US. Again low cost and low quality.

 

To answer your questions

1. No, it should not have an effect as long as your pressure is in the normal 40-90 psi range.

 

2. One week to 10 days is fine, two weeks starts pushing it a little.

 

3. Yes it can but it would be safer with a capillary tube restrictor you trim for your exact conditions. Ball valves get bumped and require adjustment. I tried a needle valve myself but found it slowed down over time and my waste ratio was reduced to a point where it affected the membrane.

3a. More flush or waste is good but probably not necessary given your TDS. One problem is increased waste reduces the pressur at the membrane which lowers water quality and water production both.

 

Did you monitor your rejection rate when the membrane was new? You really should do this periodically to establish a baseline and a pattern. For all you know it may have been 93% out of the package, that is common. It talking to places that test membranes I am told the average off the shelf rejection rate is in the 96% range not 98% like most are led to believe. Spectrapure told me they fail more membranes than the aqccept based on their bench testing if that tells you anything.

 

If you look at the Spectrapure sale flyer you will find many prefilters, carbons and membranes on sale. Their hand tested 90 GPD membranes are only $45 and the batch tested versions are only $35. The low micron prefilters and carbons ar also on sale. They are all I buy anymore myself and the quality is phenominal.

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Ok. I understand these things a little better now. I am still using the ball valve, I have marked each time I adjust it so I can tell if it gets moved. I test the 4:1 ratio periodically to make sure. My TDS is now climbing again so I am shopping for a new DI and its about time to replace 1 and 2 again.

 

I WILL be ordering some lower micron 1 and 2, and I am curious/interested in adding another canister and pre-filter..would there be any advantage to that?

 

Also, I went to Spectrapure and noticed the new "MAX Cap" Great idea but I'm not spending $800 on that right now but I do like the new filter they have that they say can be added pre-DI and guarantee less money be spent over time by saving DI life. I like that idea! What do you think? Is it possible/Worthwhile?

 

Also after re-reading everything( which I will probably do again, your information is rich :P ) I kinda realize ideally I should put a new flow restrictor in there - should I get a Coralife model? Do I have to? Is there a better option?

 

Thanks again AZ sorry it took a min to get back to you

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I would buy a capillary tube flow restrictor from the Spectrapure site, $5, then trim it according to the included directions for a 4:1 ratio.

 

Yes, you do want and need a better prefilter and carbon block. You say your TDS is going up. Test the TDS in three places, this wil tell you what is happening with your system. First test the tap water TDS, then triple rinse the TDS meter and glass or whatever you are capturing the water in in DI, next test the RO only TDS before the DI, again triple rinse and finally test the RO/DI and do a final rinse so the meter and glass are clean for next time.

 

Your RO only rejection rate or removal efficiency should be in the 95-98% range or you are depending on DI resin to prop up a poorly performing RO membrane. If the RO TDS is OK then its the DI that needs replacing.

 

There is no advantage to an additional prefilter unless you are having major sediment or particulate problems and even then a single 0.5 micron ZetaZorb usually works well with its 10x increased surface area. Everything you add in front of the membrane reduces pressure and lowers the membranes efficiency and GPD. Thats why I hate to see two carbons when one is perfect for most situations if you use a quality prefilter to protect it.

 

A pooly performing membrane will cost more in DI resin replacements regardless if its the standard DI configuration or you add the MaxCap DI cartridge before your present one. I would replace a bad membrane before investing in a second DI as it will make your DI last 5 to 10 times longer or more, even a 2% increase in membrane efficiency doubles the life of your DI resin.

 

I have owned a MaxCap system for 7 years now, the first one was a single membrane 90 GPD system which was later converted to a dual membrane 180 GPD system. My current system is the one you referred to the MaxCap UHE which runs at 1:1 waste ratio and is an excellent choice for those who are concerned about wasting water. In the two years I have owned it, it has already paid for itself and is now paying me in DI and filter savings. I am making true 0 TDS or 18.2 megaohm resistivity water at about 2 cents a gallon based on my data. Can't top that with anything.

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Ok I performed the 3 tests with triple rinses.

 

TAP: 268-273

Before DI: 10-11ppm

production/DI is: 5ppm

 

The higher numbers registered when I stirred the TDS meter - unsure why that is but it is what it is.

Also, these readings of the membrane before DI are without a flow restictor so I am unsure how that will affect this reading.

 

 

 

 

 

I have two brand new 1 and 2 waiting to install, but these are Coralife replacements. My 1 and 2 canisters regrettably have some green algae on the inside of them - probably from the lack of use in the last few months - so I am ready to do some cleaning as well. At this point should I go ahead and put the Coralife filters in there? How necessary/recommended is the .2u sediment filter for $26 over say the $10 cheaper .5u?

 

My unit is a 50gpd, Spectrapure has only 40 and 60 gpd membranes and flow restrictors should I go with the 60? Also, side note, if I do need to change the membrane could I get a 90gpd membrane and matching flow restrictor and ultimately change the gpd of my unit or is there more involved with that?

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You are getting 95-96% rejection or removal.

The correct flow restrictor should help this as it will provide more pressure to the membrane and membranes are more efficient at higher pressures, up to as high as 150 psi by the way. I run my system at 100 psi.

 

I would immediately remove the prefilter and carbon and disinfect the system with bleach. If you do not have directions on how to do this, I have posted them many times here on N-R and a quick search should bring them up.

 

For now use what you have as far as new replacements, the membrane is not going to improve at this point by using better replacement filters.

 

You probably would want to go with the 40 GPD flow restrictor and trim it to fit.

 

Its up to you but personally if you are considering a new membrane I would definitely go the 90 GPD, it produces water much faster so less waiting around watching a smaller system drip....drip...drip.

You should probably price out replacements vs. a new better system like the CSP-DI. Quickly in my head a new prefilter, carbon block, refillable DI cartridge with 20 oz of SilicaBuster resin, a 90 GPD Select membrane and a flow restrictor is going to run you about $90 plus shipping even with the sale prices. A new CSP-DI is $145 complete and includes a manufacturers warranty, dual inline TDS meter and inline pressure gauge plus has higher quality canisters and speed fittings so might be the better way to go.

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My city water is lower than that you must be using a pump to achieve that PSI ? Should I look into a pump as an accessory investment to this?

Ok, I disinfected 1 and 2 and did as you said with the one at a time replacement and rinsing each one at a time. You know, I may have damaged this current membrane by not rinsing the filters prior to use - the amount of black/purpley stuff that came out when I did the carbon block! Man!

 

So, I CAN just switch to a 90gpd membrane?

 

I found some Spectrapure RO/DIs on marinedepot but most were $200+.. I am inclined to keep this unit.. Even with a new unit I would want to get the .2u sediment. I dont know, I have done lawn mowing commercial/residential for 10years now and I always tell people to ditch homeowner grade trimmer and lawn mowers for even the cheapest commercial grade units because they last so much longer with less cost of ownership and are easier to fix and find replacement parts for. Am in this kind of a situation or could this unit and parts be upgraded to be a quality unit? Should I add some pressure guages? What are their purpose?

 

Edit: Also, my TDS has risen to 7ppm. The DI must be deteriorating quickly!

Edited by twichstile

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The sale prices are only good directly from Spectrapure:

http://www.spectrapure.com/email/customer-appreciation.html

 

$145 gets you a killer system complete.

 

Yes you canswitch to a 90 GPD membrane ($30 batch tested or $40 individually hand tested and guaranteed) along with a matched flow restrictor for another $5.

 

If the DI is anything other than 0 TDS it is exhausted and dumping weakly ionized substances back into your treated water, usually nitrates, silicates and phosphates get released first and are hard to detect with hobbyist grade TDS meters so are probably higher than you think

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Ok thanks DesertRat I appreciate all your help! If I got the new unit should I go ahead and get the .2u sediment filter? I mean .5 is better than what I have but now I am a little more interested in higher quality stuff if I am going to save money in the long run.

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I prefer the 0.2 myself. I switched my olf MaxCap to a 0.2 before i sold the system and my UHE runs the 0.2 with great filter life and performance. The more you can do to protect the carbon block and membrane the longer thay will last and better they will perform too.

If you are going to go that route its worthwhile to have a low range chlorine test kit and pressure gauges before the prefilter and after the carbon block so you can monitor both pressure drop across the filters and chlorine breakthru to gte maximum life out of the filters. by doing this you can avoid the 6 month filter replacement "rule" since its usually a carbon fouls and plugs which is why it does not last. With better protection you can extend that out several months or more as long as you monitor their conditions.

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That sounds really nice! Wow, yea that would be great if a .2 could last a little longer since it costs so much more. So, is this the best way to reduce maintenance cost?

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It works for me. The original 0.2 went 18 months and was still in great shape when I hanged it. I would not try to extend past the 6 month mark though without monitoring pressure drop and chlorine breakthru though.

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OK i'm going to go for this, what pressure gauges do I need to get? Two identical ones before and after filter #1? How much pressure drop do you expect and look for to gauge filter condition?

 

 

Filter 2: What brand chlorine test kit would you recommend? And I would test the water after the carbon block to see what chlorine may be going to the membrane, or after #1 to see how much chlorine is going into carbon block?

 

 

 

My current system is the one you referred to the MaxCap UHE which runs at 1:1 waste ratio and is an excellent choice for those who are concerned about wasting water. In the two years I have owned it, it has already paid for itself and is now paying me in DI and filter savings. I am making true 0 TDS or 18.2 megaohm resistivity water at about 2 cents a gallon based on my data. Can't top that with anything.

 

---What exactly makes this unit run so efficiently? It seems the Maxcap canister is a SUPER Di. This unit also has computer..what does it do?

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It MAY still be good, the ad says "till Sept 30th or as long as supplies last"

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Many membrane housings have a place for a back mount pressure gauge to screw in directly. If yours does not you would need two inline pressure gauges, one in front of the prefilter and the other after the carbon block, before the membrane.

 

Spectrapure sells a low range chlorine test kit on their website, its very inexpensive.

You test the chlorine either after the carbon block or after the membrane either way.

 

The sale ad says Sept 30 or until supplies are gone, I would call if it were me.

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Thanks for all your help and patience Desert Rat :D

Edited by twichstile

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its worthwhile to have a low range chlorine test kit and pressure gauges before the prefilter and after the carbon block so you can monitor both pressure drop across the filters and chlorine breakthru to gte maximum life out of the filters.

 

How do you monitor the chlorine breakthrough?

 

Is there a daily test you can do, similar to using a TDS meter?

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