Iron Removal Help with water results

[barlow96]

Hello,

We have iron in our well water.
Test results:
Iron - .0892 mg/l
Hardness - 99
pH - 7.3
GPM - (based on pressure tank test) - 7.5 GPM

I know the iron results are not high, but it is noticeable. Also i believe we have manganese in our water as the toilet holding tank has a black residue along the inside.

There currently is some type of backwashing filter installed now (around 12 years old), that i would like to replace as it doesn't function properly and the valve just started showing and error code (ERR 3) which means the cam isn't going back to the home position. I did a flashlight test and there isn't any media rise during backwash, so it isn't working properly anyway. I would like to start new and I was thinking of the terminox system but i want to check on here first.

Thank you

 

[Reach4]

Hardness - 99

1. Units? (grains or mg/l)

I know the iron results are not high, but it is noticeable. Also i believe we have manganese in our water as the toilet holding tank has a black residue along the inside.

2. What is your manganese number?
3. Does your black residue react to liquid chlorine bleach?
4. was your test sample of your raw water or after your backwashing filter?

There currently is some type of backwashing filter installed now (around 12 years old), that i would like to replace as it doesn't function properly and the valve just started showing and error code (ERR 3) which means the cam isn't going back to the home position. I did a flashlight test and there isn't any media rise during backwash, so it isn't working properly anyway.

With significant iron, I am surprised you could shine a flashlight through the tank.

Terminox (a brand name solid manganese oxide ) and I think it is pretty much the same as Pyrolox and Pilox, and if so requires a very high backwash gpm. Make sure your system can provide that before getting a system. 7.5 is barely enough to backwash Katalox Light in a 10 inch tank. With a heavy solid (non-coated) media, it might do a 6 inch tank. Backwash GPM is proportional to the square of the diameter.

 

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[barlow96]

ok, so hardness is 99 mg/l.

Iron is actually low at 0.0892 mg/l
Magnesium is 7.9 mg/l

I did not test for manganese and I hoping it is just the iron or magnesium i am noticing in the toilet tank.

concerning the black residue on the toilet reacting with chlorine, what do you mean by this?

The raw water from the pressure tank does not have a smell and that is where the sample came from. when i collect a sample from the pressure tank and add chlorine, i did not get any precipitates other then some white flakes.

backwash rates currently are (with filter in back wash mode and pressure tank settings at 40 psi on 60 psi off) 12.85 GPM @ 60 psi and 10.58 gpm @ 40 psi .

Maybe i just ditch the filter set-up and go with a softener due to the low levels or iron and magnesium?

Thoughts?

 

[Reach4]

concerning the black residue on the toilet reacting with chlorine, what do you mean by this?

Chlorine bleach will kill mold/mildew. The appearance should change. Manganese compounds are not going to be affected much by a moderate treatment of household bleach. General sediment can be black too.

Maybe i just ditch the filter set-up and go with a softener due to the low levels or iron and magnesium?

I suggest a lab test that includes manganese. But the softener may be the best choice. I am not a pro.

backwash rates currently are (with filter in back wash mode and pressure tank settings at 40 psi on 60 psi off) 12.85 GPM @ 60 psi and 10.58 gpm @ 40 psi .

How are you measuring that -- seconds to fill a 5-gallon bucket? Impressive. How do you reconcile those numbers with the 7.5 gpm number in your original post?

 

[barlow96]

So the original 7.5 GPM was an old number from lower settings in the pressure tank. I figured i would go down and manually set the valve to backwash (error code went away after unplugging unit from wall) and measured time it took to fill a gallon jug at 60 psi and then when the tank got down to 40 psi...the backwash time is set for 14 mins currently.

 

[Reach4]

So the original 7.5 GPM was an old number from lower settings in the pressure tank. I figured i would go down and manually set the valve to backwash (error code went away after unplugging unit from wall) and measured time it took to fill a gallon jug at 60 psi and then when the tank got down to 40 psi...the backwash time is set for 14 mins currently.

The test should have been what the flow rate is after 10 minutes. I would presume the pressure would stabilize to something much less than 40 psi once the pressure tank has given out its stored water.

 

[Bannerman]

Black residue within a toilet tank, is a common result of manganese, not magnesium.

Magnesium and calcium are the most common cause of hard water, which a salt type softener will remove and replace with sodium. While manganese may sometimes also be removed with a softener depending on quantity, the softener's hardness setting will need to be increased accordingly, thereby resulting in higher salt use and lower efficiency. In addition, as manganese will accumulate on the surface of a softener's resin granules, a softener will require periodic but ongoing manual maintenance to remove any accumulation.

A lab test of your raw well water should provide a report of all water conditions, and the quantity of each element.

Suggest posting a photo (low resolution) showing your existing unit's control valve. As it is only 12 years old, if your unit is equipped with a high quality control valve such as a Clack or Fleck model, it maybe best to simply rebuild and re utilize it with new media. It's likely the existing valve can be simply and economically repaired, especially if you are moderately handy and willing to perform the task yourself.

Specify the diameter and height of your existing media tank.

Do you know or have you measured the flow rate your well pump is capable of delivering?

I suspect your existing media has not been backwashed at a sufficient flow rate, or possibly not frequently enough, which has likely caused the media to settle and compact to form a solid mass, similar to concrete at the bottom of the tank.

Terminox is a proprietary media, which is made from a mined form of solid manganese dioxide. As the media granules are solid, they will be heavy and will require a substantially higher Backwash flow rate compared to the usual recommended and more widely available Katalox Light media which uses a manganese dioxide shell infused onto a lightweight zeolight base.

While the Backwash and Service flow specifications for Terminox do not seem to be widely available online, I see it is listed as similar to Pyrolox although the backwash requirement is specified to be slightly less than Pyrolox.

The recommended effective Service flow for Pyrolox is 5 gpm or less per square foot of tank cross section, so if your tank diameter is 9", this is only 2.2 GPM, or 2.7 GPM for a 10" tank. Exceeding those flow rates will reduce the effectiveness of iron & manganese removal, so some amount of those elements will remain in the water exiting from the filter, and will increase as the flow rate is further exceeded.

The recommended effective flow rate for Katalox Light media is 6-12 GPM per ft2, so a 9" diameter tank of KL will support upto 5.3 gpm, whereas a 10" diameter tank will support upto 6.5 gpm to fixtures.

The recommended Backwash requirement for Pyrolox is 25-30 GPM per ft2, so a 9" tank will require 11-13 GP or 14-16 GPM for a10" tank. Although Terminox should require a lower backwash rate, it will likely continue to be substantially greater than KL. The recommended BW rate for KL is only 10-15 gpm/ft2, or 4.4-6.6 GPM for a 9", or 5.4-8.1 GPM for 10", which your well pump will likely be more capable of supplying.

 

[Reach4]

The recommended BW rate for KL is only 10-15 gpm/ft2, or 4.4-6.6 GPM for a 9", or 5.4-8.1 GPM for 10", which your well pump will likely be more capable of supplying.

5.4 gpm for KL in a 10 inch tank is too low, for normal temperatures at least. I suspect the marketing people had too much influence on publishing that number.

Given that, I similarly suspect that numbers published for other media may also be sub-optimum.

 

[Bannerman]

I similarly suspect that numbers published for other media may also be sub-optimum.

Recommendations as published by Ditttohead.

Backwash rates by Media

 

[Reach4]

That comes from the manufacturer's data, which I blamed on the marketing people.

Katalox Light.

Hello to all, I was looking at new posts and seen the one on Katalox-light and wanted to know more?I also have have the same set-up with a holding tank (low yielding well) ok my main concern, can I use this media with a fleck 7000 and 10x54 tank and just backwash once and a while,just water or...

terrylove.com

 

[Bannerman]

That comes from the manufacturer's data,

Maybe so, but he also advised, for optimal performance, always utilize the highest backwash rate if at all possible.

As KL's highest specified backwash rate will result in only 30% bed expansion, it would then seem, the highest recommended backwash rate could actually be exceeded somewhat, without risk of exceeding the 50% expansion limit typically utilized for lighter weight media such as water softener resin.

 

[barlow96]

sorry for the delay...so I have the 10'' vortech terminox filter 10'' x 54''(with 1.5 cu ft media and gravel) with pentair 263/740F autotrol valve (installed in 2015). I shined a light through the tank and at rest the media is at 37.5'' height. During backwash the media rises almost to the top of the tank.

post filter test results:
I had lab guy come to my house for some on-site sampling (he wasnt using test strips but rather drops and cylinders for levels)

iron - <.05 mg/l
Manganese - > 0 but less than .03 mg/l
hardness - roughly 6-6.5 grains

He is saying i do have a slight mag problem and very low iron problem post filter. He suggested to rebed the filter (even though terminox state 25 year life he said that is probably not true) and look for an appropriate water softener to handle my moderate hardness and low iron/mag issues (both are dissolved form).

Based on the results post filters, any recommendation on the type of water softner? I am confused as to what type would be best for the low iron/mag and hardness. family of 4.

Thank you

 

[Reach4]

With these levels, what would be the point of rebedding the Terminox?

A softener with 10x54 inch tank with 1.5 cuft of resin would be fine, and would cause you to regenerate about every 14 days. Alternatively you could go to a 12x52 inch tank with 2 cuft of resin.

A Fleck 5800SXT would be an appropriate valve.

 

[barlow96]

I guess just to start fresh with new resin as it is approaching 11 years of age. I realize it is still working, but i doubt the lifespan of 25 years. Is there a specific regenerations for the softener that is favorable (countercurrent or co-current)?

 

[Reach4]

If that water test is truely from the drain valve at the pressure tank, that would be before the backwashing filter. That water test does not show a reason to have a Terminox backwashing filter. It raises the question as to why it was there in the first place. But since it is there, fine, but why rebed it?

If, on the other hand, the sample actually came from after the Terminox, then that filter is working fine with the current media.

So which is better -- upflow brining or downflow brining? Each has its advantages. Upflow brining calls for slower brine injection, and that makes the regen take longer. Upflow is slightly more brine-efficient. Downflow brining is more common, and if the parts differ, the downflow parts should usually be more available/cheaper. The piston differs in the Fleck 5800 and 5600, and I am not sure what other parts (other than the injector) differ.