Field Testing "Chloramine Buster" RO System

[Pat_in_NC]

Since September I have been field testing a new RO system which was put together by Al Johnson of Rocky Mountain Discus. He sent it to me free of charge to test for its ability to remove chloramines from different water supplies in different parts of the country. There were no strings attached and he did not ask me to post this. I was skeptical because my previous experience with a Kent Marine RO unit was that it was completely ineffective at removing the ammonia component of chloramines (ammonia readings were identical in tap and product water). While carbon pre-filters readily remove the chlorine component of chloramines everything I had read and heard suggested that RO membranes were not generally effective in rejecting (removing) ammonia from chloramines treated water (unless that have DI resin which is expensive and needs frequent replacement) at least under normal tap water pH range (7.2-7.8). My water company went to chloramines treatment about a year ago and it caused a lot of water quality issues so I was very interested to see if there was in fact an RO unit which would work

The R.O. system is a 5 stage system with 1) sediment filter 2) Two Carbon Block filters 3) 50 GPD R.O. membrane 4) A final stage which I believe is a final polishing stage with carbon. Below is a copy of my first tests in September-which I have repeated in November and last week (i.e. February or 5 months since I first set it up). All of the tests have given incredible (at least to me!) results with regard to ammonia rejection.

pH (Accumet pH meter--freshly calibrated)
1) Tap: pH 7.8
2) Waste: pH 7.9
3) Product: pH 7.2

Conductivity (Thermo Orion Conductivity meter--freshly calibrated)
1) Tap: 183 mS
2) Waste: 210 mS
3) Product: 0.1 mS (not sure how accurate the meter is in this range but definitely less than 2 mS)

Hach Total Chlorine Test
1) Tap: 3.5 mg/L
2) Waste: 0 mg/L
3) Product: 0 mg/L

Hach Total Ammonia Test
1) Tap: 1.0 mg/L
2) Waste: 1.1 mg/L
3) Product: 0.05 mg/L

Tetra Ammonia Test
1) Tap: 1.5 mg/L
2) Waste: 1.5mg/L
3) Product: 0.1 mg/L

Wardley Nitrite Test
1) Tap: 0 mg/L
2) Waste: 0 mg/L
3) Product: 0 mg/L

Tetra Nitrate Test
1) Tap: <5 mg/L
2) Waste: <5 mg/L
3) Product: <5 mg/L



I have repeated these tests every 2 months and found virtually identical results. I have been running the system every day for about 4-12 hours/day and over the last 5 months I did not change or replace anything. Just this weekend I replaced the sediment filters and two carbon block filters (total cost $36) as recommended by Al. Finally I was so happy with this system I have upgraded it to a 100 gpd membrane (which also shows 95% rejection of ammonia) and the rate of product water production has been clearly improved. I have been using the product water primarily in my breeding tank for the last 5 months as a 2:1 mix with chlorine filtered aged heated tap water (which has been aged with a cycled filter to convert the ammonia to nitrate). My last batch of eggs had a 97% hatch rate in this water (90 uS conductivity) and the babies from this hatch are feeding off the parents sides.

I am not trying to be a salesman for Al Johnson's RO setup-but I thought that others with problems with chloramines might be genuinely interested in the success I had with this setup. Also until testing this system I had basically assumed that all RO systems were ineffective at removing ammonia from chloramines. I was happily surprised to be wrong on that assumption. High quality RO systems can remove chloramines--at least I can verify that Al's Chloramine Buster system does in fact work with chloramine treated water!

HTH,

Pat

[Paulio]

This is a great idea however not a new one. I have run dual carbon blocks (1mic and 5 mic) on my R/O for years. A buddy of mine did one better and added the big housing and cart. I think it is 20" or something. Im sure someone here knows better than I about as far as sizes and what you need. I think the total cost to add an extra carbon block is around $30 and probably the same to add a mix bed D/I as well. Of course if aquarium gear manufacturers all started selling these units and/or upgrades they couldnt dip our pockets every month for Amquel or the like.

Just my 2 cents

Paul

[Pat_in_NC]

Hi Paul,

I don't think it is the carbon blocks which allow this system to work. All RO systems have some kind of carbon pre-filter to protect the membranes from damage by chlorine. Moreover the test results clearly show that the RO membranes are rejecting 95% of the ammonia into the waste water and leaving only 5% left behind. The kent marine RO membranes (which did lower conductivity i.e. rejected other salts) simply didn't do this--same amount of ammonia in product as in tap and waste. I have heard many similar stories of RO membranes having difficulty in rejecting ammonia. My guess is that high end membranes have this capacity but low end membranes don't. Unfortunately there is no way to know for sure unless someone has explicity tested the membranes for ammonia rejection. Hence why I thought this post might be useful for others.


Cheers,

Pat

[brewmaster15]

Hi Pat,
I'm glad it worked out for you. :)

-al

[RandalB]

Hi all!
I was hesitant to get in on this one as someone who makes RO units, but It appears that you guys are laboring under a misconception. The misconception that RO units do nothing against Chloramine.

Actually, RO membranes will reject 85-96% of the ammonia content from Chloramine depending on the Feed water conditions and the manufacturer. The Dow Filmtec 1.5" residental membranes I use will typically reject 96% at rated pressure, the 4" commercial ones will reject 99%. The addition of extra carbon prefilters will help by catching more before it hits the membrane and the GAC post filter will catch even more.

As your tests indicated Pat, the unit is doing an excellent job of catching the ammonia. It is unfortunately not a "special" membrane that is doing the job, it is the combination of carbon and the membrane that is doing it. The addition of a DI cartrige would eliminate the residual ammonia completely as would another GAC filter or two.

Also, Di is not that expensive and when used post RO it doesn't have to be replaced all that often. (2500 Gallons+ just like the carbon post filters)

Hat's off to you Pat for testing and posting the results.

More information about this topic would definately be interesting.

Regards,
RandalB

[Pat_in_NC]

Hi Randal,

Thanks for the post and encouragement. My point was not that this system was completely unique but that in my own experience and that of several others many RO units (presumably the ones with lower quality RO membranes?) do not reject the ammonia component of chloramine at all. Since this is not a common parameter to measure in the industry (I have never seen ammonia rejection mentioned by any of the common distributers of RO equipment) there is no way to know this ahead of time. On top of this the real rejection rate can be strongly influenced by pH (as I understand it is much easier to reject NH4+ than NH3) and as you said water pressure going in to the membrane (which is why I bought the booster pump from you a few weeks back). So the fact that Al had gone to the trouble to get real world data for the ability of this system to handle chloramines I think should be applauded (as I understand it I was one of several systems he sent out to be tested). I only wish there was more clear information about the performance of different RO systems with chloramine treated water. I know my research into this last year made it clear to me that many (most?) of the people I talked to in the water purification businesses (Culligan, Spectrapure, AquaFX) don't have a clue about how their systems handle ammonia.

On the issue of carbon block and activated carbon removing ammonia. Maybe I'm wrong here but my understanding and the results of several different tests (including those posted above) suggests that neither carbon block or granular activated carbon does anything to remove ammonia (the amount of ammonia in the rejection water is always same or slightly greater than in the input tap). Of course carbon is very good at removing the chlorine but under normal flow rates (50-200 gpd) does not absorb any significant amount of ammonia. I heard that Calgon was working on a type of activated carbon that did absorb ammonia but I believe it was impractical for home use (high cost and very long residency times required).

Anyway Randall I think if you can demonstrate that the RO membranes you have in your systems reject ammonia that efficiently with normal pH and normal house water pressure that you should let people with chloramine-treated water know about it! There are lots of people with chloramine treated water now a days (I think close to 30% of SimplyDiscus members on a recent poll?) and there is very little good information about how various water purification systems handle it. A number of water purification companies claim to remove chloramines from tap water with carbon only filters which, in my opinion, is a very misleading claim because it almost certainly leaves behind all the toxic (at least for fish) ammonia.

Perhaps more people can test their RO systems for ammonia rejection and we can make a list of manufacturers that are selling systems that truly "aquarium grade" and remove ammonia and those that don't. The thing that makes Al's system special is that it has been tested and it works. There are certainly other RO systems out there that don't. I think if one is looking to buy an RO system and you have chloramine treated water this should be a critical issue in the decision process.

Randall if more people were like you and Al and actually tested for ammonia rejection with their systems, then this would be far less of a problem. I know when I bought my first RO system a little over a year ago (which I now use for parts) I encoutered an amazing amount of disinformation about chloramines, carbon, RO systems, Di systems. It turns out that ammonia is not so easy to get rid of and no one wants to admit that their systems (which were designed to work on chlorinated water) don't work well on chloraminated water. So they BS you instead. I personally got very frustrated by the ignorance and disinformation in this area.

Back to work,

Pat

[RandalB]

Pat,
Kudos to you and Al for the testing! I have always felt that the water filtration industry has ignored the Chloramine issue.I am also sorry, I thought it was common knowledge about the 96% rejection rate on 5 stage TFC RO units. I was under the impression that the residual 4-5% was the concern.

You are completely right about people in the industry not knowing about ammonia. I had to contact a chemist at DOW to get exact numbers on ammonia rejection on the filmtecs. I have not asked a customer to do exact measurements in Chloramine, but people who have bought units from me in areas that have chloramine report very low or non measurable ammonia levels post RO. I personally recommend DI for Chloramine treated tap water as I find the % missed on the ammonia unacceptable. The $25.00 add on for DI with $10.00 replacement cartriges is a small price to pay for 0.0 ammonia levels IMHO. The variables involved in obtaining the 96% rejection (Pressure, pH, TDS and temp) make it too dangerous for me to assure someone that their water will be safe on the other end. (I always take the water purity to the extreme when discus are involved)

The activated carbon does actually help somewhat as it assists in breaking the chlorine/ammonia bond and traps some of the ammonia with it. The GAC at the end stage helps a little too. I measured ammonia with an Ion specific meter which shows reduction from source with Carbon only. Not a tremendous amount but there. ( I am working on a non-RO Tapwater dechloramine system) KDF 55 also shows a reduction. But straight activated carbon will not do the job.

I agree with you totally about the testing of brand name units! I think that would be a great resource and an interesting thread. It might be a little difficult to judge though considering the variables in feed water. A brand name unit might reject 96% on one water supply and less on another. If we had people testing on the same water supply with the same parameters it might work. I have been informed by a DOW chemist that most TFC membranes when operating at rated pressure will reject 85-96% of ammonia. So a quality TFC membrane should do the job somewhat but not completely.

Finally, I agree that there is an amazing amount of BS going around the RO industry PERIOD. Not just restricted to the chloramine issue. Pricing, effectiveness and ignorant salespeople are also serious problems in the industry. Look at Al's and My price points and ask why the others are charging $350.00 for an RO unit. Especially considering ALL RO UNITS ARE BASICALLY THE SAME!. Try to get a definate answer about feed water conditions from a major manufacturer (be prepred to wait a while...) or ask a salesperson at the home improvement store to explain the difference between TFC and CTA membranes and see how it goes. I can perfectly understand why the layman gets frustrated with this crap. I'm glad I can do my part here on simply by making myself available for questions and providing a quality product at a great price. I just wish more people would step up and ask them. I'm also glad that businessmen like Al take the inititive to experiment where my limited resources hinder me.

Keep it coming Pat and thank Al for stepping up to the plate and doing something about a serious problem for discus keepers everywhere! (Your town could go to chloramine tomorrow!)This is the sort of thread/information that makes a difference in the hobby.

Best Regards,
RandalB