Battles with manganese

[WellOff]

OK, more to the story...

I ran several more tests, striving to establish some sort of consistency.

First test was to check H2O2 residual (always a key thing to check), I'm seeing 1.7ppm: that's the highest I've seen. (so, to all those that might think that my injected solution is too weak or too little- I'm actually using TOO much!) Keep reading to find out why this is.

Second test was to check H2O2 at the end of the system -> "Lo" (I believe that this is less than 0.01ppm)

So, the system is managing H2O2 as it should.

Next test was for Fe, taken just after my contact tank -> 0.83ppm. This is lower than earlier readings of around 2.1ppm, and, I suspect, is why my H2O2 residual is high: lower Fe equals lower H2O2 demand, which means more H2O2 residual.

I then tested Fe at the end of the system and I got 0.87ppm. Huh? This had happened before, and sent me running in circles. Where was the Fe coming from?

I tested Fe out of my backwash filter and it came up "Lo" (less than 0.03ppm). Fearing a bad test result I ran the same test over, and I also got "Lo." So, this seemed like the carbon WAS working. So, again, why the 0.087 at the end of the system?

I ran two more tests for Fe at the end of the system and BOTH came up "Lo." Best two out of three! Apparently the first result, 0.87ppm, was bad.

At this point I felt like everything was behaving just as it was supposed to.

Next was to test for my real nemesis, Mn...

Mn post contact tank -> 0.15ppm.

Mn at the end of the system -> 0.15ppm

The outfit I bought my system from was WRONG about it being able to deal with my levels of manganese: and, recently, I was doing some research and stumbled across a document that they had that stated that Carbon does NOT deal with manganese. And, yet, they sold me the system: I have ALL correspondence on my inquires/requirements and the follow-ups on my issues.

I still have the Katalox Light test cartridge and I'm going to give it another shot.

Stay tuned!

 

[WellOff]

Finally got around to running another test.

My results were better in that I got reductions in Fe as I'd expect: before I wasn't seeing any reduction. On the Mn front, I also saw, for the first time, an actual reduction! Here's what I got (using the eXact micro tester):

Raw (post contact tank) ppm:
Fe: 5.1, 2.39, 2.37
Mn: 0.13, 0.06, 0.04

Katalox Light test cartridge ppm:
Fe: 2.05, 1.08, 2.05, 1.27, 1.24
Mn: "Lo", "Lo", 0.09

The test results just seemed to be too erratic to base a big decision on so I sent off a sample, of Katalox Light treated water, to the lab (same lab I've been using for years). Here's what I got (ppm):

Fe: 0.34
Mn: 0.037
pH: 9.25

Fe is right around the secondary MCL of 0.03mg/L. Mn is UNDER the secondary MCL 0.05mg/L- YEAH! (this matches what my taste tests came up with- with coffee I didn't get the bite like I have with my current system- almost positive that this is all about Mn!)

The high pH "should," from what I've read on KL, settle back down. I ran a good 50 gallons or so on a pre-flush and then something like another 10 gallons up to the point of taking the sample for the lab.

One point of difference between the test setup and the production one is that the production setup has a 1 micron dual-density final filter: since I used this filter housing to place the KL test cartridge I didn't have the capability of providing a final filter in the test. I have never tested my water after the carbon tank AND before the final filter in which case I don't know how much Fe and Mn is actually passing through the carbon tank. I've got a spigot between the two, in which case it's easy enough to take a sample. Just curious as to how effective the final filter is given that all my lab tests have come back with Fe being pretty much undetected.

 

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[ditttohead]

I am fairly sure you did this, but I didn't want to read through the whole thread to confirm it but... be sure your test cartridge is installed with the water flowing into the outlet, and out the inlet. If you run it in reverse your results will not be accurate. Sorry if you already stated this is how it is done, just don't have the time to read through the whole thread. Keep us posted!

 

[WellOff]

Yes. flow was reversed and the end of the cartridge with the rubber washer was at the top of the filter housing. Ran 40 - 50 gallons at roughly 2gpm to 3gpm. Dumped in bleach and ran @ < 1/2gpm for a while: don't recall smelling bleach in the water samples.

I wish that I could have confidence in the eXact mico readings. Though it did tend to show the trend, it wasn't very convincing: having multiple tests comong up with readings which were significantly different between the tests (and same water sample).

Again, the lab reports Mn as 0.034 ppm. Best I'd ever encountered (testing by the lab) was 0.097 (the raw water was only 0.076!). The fact that this test didn't have the benefit of a final filter yet it worked on Mn far better than my existing system (which really was never shown to really put a dent in the Mn) seems to indicate a strong likelihood that the KL does work. I would have liked to see how the KL and the same final filter would perform: next best thing is to, as noted above, test Mn levels before the final filter and after the carbon (backwash) filter- I'll try and run some tests before the end of next week.

 

[ditttohead]

The eXact test kits work very well, but like so many test kits, once they get down to the lower end or upper ends of their limits, the results start to get inconsistent.

Checking gas mileage on a car is simple if your test results show you are getting between 34 and 36. If you are trying to determine if you are getting between 35.339 and 35.421 mgp, the results are very difficult to quantify. hope the analogy makes sense.

Keep us posted!

 

[Reach4]

Yes. flow was reversed and the end of the cartridge with the rubber washer was at the top of the filter housing.

Nice catch, Ditttohead!

 

[WellOff]

What did he catch?

 

[Reach4]

What did he catch?

Reversed flow.

 

[WellOff]

Regarding the reversed flow, yes, that's one of the things required for the test, I'd run this test now twice, both times following all the information I was given for performing the tests.

On the accuracy of the eXact micro tests, ITS (manufacturer) claims 0.01 for Mn with a range of 0.01 to 1.5, down to 0.01 for Fe with a range of 0.08 to 2.5 (accuracy for the lower end of the 0.06 to 6 total range; it's 0.1 between 2.51 and 6). While my tests are on the low side they are still within the resolution range (the deviations in the tests is quite substantial and, I'm pretty sure, not due to the operating range); I would fully expect to have reasonable, repeatable accuracy. That said, here's the test results I just took from after my carbon tank and before my final filter:

Fe: "Lo"; 0.41; 0.55
Mn: 0.21; 0.08; 0.07

Based on that trend if I were to continue testing I'd eventually get very high readings of Fe and very low readings of Mn! Again, I have little confidence in the tester. I tried stirring the water sample just to make sure I wasn't getting some sort of settling going on (doesn't make sense that it would be happening in such a short amount of time, but I figured I'd do it anyway). BTW - sample's water temp was just under 53 degrees.

Even with the lowest Mn reading of 0.07, which I highly doubt, the lab test number for MN from the KL sample is still half. The Fe seems to stump me, but I am pretty positive that the final filter has been catching a fair amount of it: lab tests on my production water system have always come back ND, so what the carbon tank isn't trapping the final filter is. I'd figure that if the KL is followed by my same final filter that I'd also end up with these results.

I'm going to send off a sample post carbon tank and pre final filter to the lab (on Tuesday). Won't likely have numbers for another week and a half.

 

[WellOff]

Just got the lab results back (yeah, it's been two weeks!). Here's what I got back for the efficacy of the H202 and carbon backwash filter (my existing system less final filter):

pH: 6.95
Fe: 0.30
Mn: 0.165
Hardness: 63.8

Comparison (less final filter)

pH Fe Mn Hardness
Current system 6.95 0.30 0.165 63.8
Katalox Light (test) 9.25 0.34 0.037 99.5

In conclusion, the KL drastically reduced Mn: reduction by the carbon is basically non-existent. Fe levels stayed about the same, acceptable: based on previous lab tests that showed Fe to be either very low or not detectable I'd have to believe that all this time the final filter had been essentially removing the remaining Fe (in ferric state). The increased pH levels from the KL are, from my understanding, temporary and would abate with use. I don't quite know why there's an increased hardness from the KL, or even if this presents an issue.

At this point I am satisfied that the tests show that by exchanging my catalytic carbon with KL I would be able to, finally, mitigate my Mn issues, while still retaining the existing high levels of water quality.

 

[Reach4]

pH Fe Mn Hardness
Current system 6.95 0.30 0.165 63.8
Katalox Light (test) 9.25 0.34 0.037 99.5

Thanks for the update.

I have to think that the KL will be more effective against iron in the real setup. If the flow rate through the small test filter was 2-3 gallons, the equivalent rate through the 1.5 cuft of KL will be much slower, letting the KL react more.

I think your hardness test is in ppm, so that would still be less than 6 grains.

 

[WellOff]

The flow rate that I was instructed to use for the testing was about 1/2 gallon/minute if I remember correctly: it was VERY low/slow. It would be nice if there would end up being less loading on the final filter, but, really, it's not a big deal: changing out the filters is relatively easy, and given that I'd be rid of the Mn, finally, makes it a bit more tolerable.

The hardness might reduce with drops in the pH level (that I expect will occur). Just kind of put it out there as a data point in case anyone else sees this. I'd like to return back to report on things a while after making the switch: might be a couple months or so. Will have another lab test run just to be consistent.

 

[Tech1]

WellOff,

I will tell you that a Katalox Light system will be your best friend in this situation. A cartridge will not last you or will be fully adequate for treatment. Build a KM system IAW the materials below.

1 10x54 media tank with riser tube.
1 DF control valve set to a 6.2 gpm backwash with upper basket strainer, 3" of 3/8 propylene line, and 1 3/8 John Guest check valve allowing air to be pulled in.
1.2 cubic feet of KL.
13.2 lb of gravel.

Replace anode rod in water heater with aluminum anode rod.

Put it all together and install. Clean KL system periodically with Oxydes-P. Problem solved.

 

[Reach4]

Replace anode rod in water heater with aluminum anode rod.

Addressing this part only, a powered anode would protect as well as a magnesium rod and would not help generate H2S. It costs significantly more than the aluminum rod however. I expect to move mine to my next WH.

 

[Tech1]

Addressing this part only, a powered anode would protect as well as a magnesium rod and would not help generate H2S. It costs significantly more than the aluminum rod however. I expect to move mine to my next WH.

When the magnesium anode rods break down they give off the sulfide smell. An aluminum anode rod will not give off the same smell. All the anode rod does is protect the water heater. Its 20 dollars at home depot.

This is a common issue that I run into with customers. They replace the water heater and a day to a month down the road the water stinks. Replace it with aluminum and there is no more issue. Very common.

 

[ditttohead]

WellOff,

I will tell you that a Katalox Light system will be your best friend in this situation. A cartridge will not last you or will be fully adequate for treatment. Build a KM system IAW the materials below.

1 10x54 media tank with riser tube.
1 DF control valve set to a 6.2 gpm backwash with upper basket strainer, 3" of 3/8 propylene line, and 1 3/8 John Guest check valve allowing air to be pulled in.
1.2 cubic feet of KL.
13.2 lb of gravel.

Replace anode rod in water heater with aluminum anode rod.

Put it all together and install. Clean KL system periodically with Oxydes-P. Problem solved.

10x54 tank is based on what? Normal maximum flow rates, pH, etc all need to be considered then sizing a system, not just a generic system size of 10x54. If is a larger application then a larger tank may be a cheap and simple improvement. As to the filter, it is a pilot test to determine the effectiveness of the media in a specific application. This is a simple and inexpensive way to determine if a certain media will work in a desired application prior to investing in a full sized system.
The DLFC rate is actually based on a water temperature, not just a generic number that is shown on a chart. While it can be simplified to a chart, water temperature is critical to know when properly sizing KL. Also, field testing has shown that higher backwash rates are preferred. The manufacturer tends to exaggerate the nubers on KL. We bring it in by the container loads and most of our customers have increased the backwash rates at least 20-30% higher than the manufacturers recommendation with excellent results.

A top screen should probably be avoided with a KL system instead an umbrella (commonly used with turbulators) should be used. The top screens tend to foul with iron/manganese.

1.2 CF of KL... just use 1.5

13.2 pounds of gravel... depends on the mesh etc... but this is kind of silly, just use approximatel;y 15 pounds of #6 or 1/8" gravel for the underbedding.

 

[WellOff]

Hi, folks!

Thanks for the inputs.

I'd LOVE to be able to get on this (once and for all), but summer is the time that I need to get lots of other thing done. I tend to have more time for stuff like this early-to-mid spring.

I'm still wanting to know whether I can get KL to pass H2O2 through to my distribution lines to help keep them sanitized.

I've got an aluminum+zinc anode rod in my WH. Haven't checked it recently (installed about 3 years ago?). Have thoughts about just going with a powered one.

When I'm ready to switch to KL I'll be hitting up dittohead on spec-ing it out.

 

[ditttohead]

You bring up a good point. We just moved to a new facility, 30,000 sf and our time is spent daily in organizing and trying to keep up with shipping. I have added (how much chlorine/H2o2 does it take to get through the KL media). This will actually be one of my more entertaining tests. So many of the tests we do are a little mundane.

 

[WellOff]

You bring up a good point. We just moved to a new facility, 30,000 sf and our time is spent daily in organizing and trying to keep up with shipping. I have added (how much chlorine/H2o2 does it take to get through the KL media). This will actually be one of my more entertaining tests. So many of the tests we do are a little mundane.

Looking forward to hearing what you find out. I wouldn't mind doing some testing, but I'm WAAY bandwidth challenged right now.

 

[WellOff]

Hi, folks,

I just got around to measuring my H2O2 residual post contact tank and... 74ppm! From my kitchen faucet I measured 4.4ppm, which, is definitely too high; further, this residual would suggest that I don't likely have distribution line issues as previously thought. So...

A while back (couple weeks?) I stuffed the Stenner pump's pickup tube further down in the solution tank thinking that maybe it wasn't actually picking up solution (should have just tested; but, I was busy and, well, one does stupid stuff when one is in a hurry!). I suspect that, and I think that Reach4 might have mentioned this somewhere, there's a bit of stagnation going on in that tank which might require mixing (it's been about 14 months since I last filled it, with 8 gallons of solution- I cut back on the total amount of backwashing so that's likely the reason why solution consumption had dropped; before that change I was probably running through 7 gallons/year; now it looks like I'm running maybe 5 gallons [have maybe 3 gallons in there currently]). I pulled the pickup back up a ways and will, after a while, test again (I figure the residual numbers to return to being more normal [about 1.6ppm]).

For myself, it looks like having H2O2 residual in the distribution lines might not be an issue that I thought it might be. This means that I no longer see it as being something that I should be concerned with vis a vis whether I get KL or not.

I'm going to drain my WH (I'm due) and take a look at the anode. It's here that I'm periodically getting odors: shocking the lines makes it go away, but it's likely pretty much all originating in/with the WH.