Water softener (& size) vs Calcite to solve Manganese

[Mswlogo]

I have a Filox filter which is getting rid of all the Iron but barely a dent in the Manganese ~0.3 mg/L

My ph is around 7.0

I think I have 2 options.

Option #1) Add a Calcite filter that might bring pH up to 7.5 (at best) with the hope that the Filox will take out the Manganese. I know that is a gamble. The Calcite would get hit with the 7.7 Iron. And would need lots of backwashing. Also Calcite will raise Hardness from 60 to ~160 and may warrant a softener. As I type this I realize this is probably a bad idea.

Option #2) Add a Softener. What size? Since the water is not hard to begin with. And no iron to deal with, Just the Manganese and Only have 2 adults (~12,000 gallons a year)

Is 1 cu ft more than enough? I know most of the time a 1.5 cu ft or bigger would be recommended. It’s hard to know because the hardness is already fine. What “capacity” does the Resin have for Manganese.

What size tank for 1cu ft vs 1.5cu ft

Does a Vortech make sense for softener?

I have a Vortech with a Clack wS1 and figured I’d just get the same for the softener. I’d get a metered setup.

Is there such a thing as water that is too soft? Do I need to do anything with 0 hardness?

One note, I would use Potassium Chloride instead of salt.

Raw well water below

 

[Bannerman]

You didn't specify the size of Vortech tank that is currently being used for the Filox media.

Although Filox is usually effective for catalyzing manganese, perhaps the 7.7 ppm iron is overwhelming the Filox, leaving little capacity remaining to remove the manganese.

A softener is not an efficient manganese reduction method as similar to iron, each 1 ppm manganese will equal ~88 ppm (5 grains per gallon) of hardness removal capacity.

Other alternative treatments may include:

Replace the current media tank with a larger capacity version to permit additional media to be utilized.

Replace the Filox media with Katalox Light media.

Inject an oxidant such as hydrogen peroxide or chlorine before the media tank, to oxidize the manganese and iron, to reduce the cataylization load on the filtration media.

For a brief writeup concerning iron, manganese and H2S reduction, see: Iron, Manganese & H2S reduction

A 9" X 48" tank is commonly utilized for 1 ft3 media
A 10" X 54" tank is commonly utilized for 1.5 ft3 media
A 12" X 52" tank is commonly utilized for 2.0 ft3 media

 

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[Mswlogo]

Thanks for all that info.

Since I only have around 0.3 mg/L (or ppm) of Manganese. That would be .3 * 88 ppm = 26 ppm (1.5 grains) right? That should be a breeze for any water softener. And my hardness is 3.5 grains.

My Filox is 1.5 cu ft. Backwashed every other day at around 13 gpm. We use 12K gal a year (very low).

I considered another media but they are all based on the same stuff and all need higher pH to get the Manganese out. Filox is one of the best and the only reason people don’t use it, is the backwashing requirements (because it’s heavy). Not because it’s inferior to any other media. I know almost any Iron removal media could do it with higher pH or Pre Oxidation.

Katalox is just the same “active” media coated with the same stuff that Filox is made of. manganese dioxide.

Oxidizing methods seemed like more monitoring and more likely to cause harm if something goes wrong than a water softener.

I had a similar setup in a house I owned very near by (iron filter then softener). In 17 years and all I did was feed it salt and have valves checked every couple years. I never knew what media was in that Iron Filter but it clearly did the job. I’d love to know what it had though, probably not Filox because it didn’t backwash nearly enough.

 

[Bannerman]

That should be a breeze for any water softener. And my hardness is 3.5 grains.

I didn't state a softener will not remove manganese, but with only 3.5 gpg hardness, it seems hardness is not an issue so a softener seems unnecessary, especially when there is an iron/manganese reduction system already utilized.

When using a softener to reduce low levels of iron or manganese, although either will cause resin fouling, to prevent excessive fouling, low pH (<6.5) is preferred.

The recommended backwash flow rate for Filox is 20-30 GPM/ft2, so with a 10" diameter tank, that will equal 11 to 16 GPM. With the substantial amount of iron being removed, it's best to backwash at the highest rate if possible, but as you are using a Vortech lower screen, the backwash rate is usually reduced about 20%, so your current 13 GPM drain rate, will be equal to 16 GPM utilized with more common gravel under bedding.

The recommended backwash rate for Katalox Light is only 10-15 GPM/ft2, thereby reducing the backwash flow rate to 5.4 - 8.1 GPM for a 10" diameter tank, or 7.8 - 12 GPM for a 12" diameter tank, which might be beneficial if you choose to increase the amount of media to 2.0 ft3 or greater.

As a trial, you might increase the Filox backwash frequency to daily for a few weeks to establish if more frequent removal of ferric iron debris, will allow the media to more effectively reduce the quantity of manganese.

 

[Mswlogo]

I didn't state a softener will not remove manganese, but with only 3.5 gpg hardness, it seems hardness is not an issue so a softener seems unnecessary, especially when there is an iron/manganese reduction system already utilized.

When using a softener to reduce low levels of iron or manganese, although either will cause resin fouling, to prevent excessive fouling, low pH (<6.5) is preferred.

The recommended backwash flow rate for Filox is 20-30 GPM/ft2, so with a 10" diameter tank, that will equal 11 to 16 GPM. With the substantial amount of iron being removed, it's best to backwash at the highest rate if possible, but as you are using a Vortech lower screen, the backwash rate is usually reduced about 20%, so your current 13 GPM drain rate, will be equal to 16 GPM utilized with more common gravel under bedding.

The recommended backwash rate for Katalox Light is only 10-15 GPM/ft2, thereby reducing the backwash flow rate to 5.4 - 8.1 GPM for a 10" diameter tank, or 7.8 - 12 GPM for a 12" diameter tank, which might be beneficial if you choose to increase the amount of media to 2.0 ft3 or greater.

As a trial, you might increase the Filox backwash frequency to daily for a few weeks to establish if more frequent removal of ferric iron debris, will allow the media to more effectively reduce the quantity of manganese.

I tried doing a Manganese test right at the output of the iron filter immediately after a back wash (and a good 20 min flush) and no change in Manganese level.

This is a really good article on removing Manganese. It says if the conditions are right a water softener is great tool for removing Manganese. Low TDS, Low Oxigen, Low Hardness, pH below 8.0. Basically all the reasons the Filox isn’t working is why the Softener should.
https://www.purewaterproducts.com/articles/treating-manganese-in-well-water

The Filox filter I put in is already conservatively oversized as it was. It is supposed to handle up to 15 ppm of iron. If I raise to 2.0 cu ft I might not be able to back wash it.

 

[Taylorjm]

So I will tell you what I did. Our water is very hard at 60 gpg, but we also had .089ppm of Manganese, and 4.16 PPM of iron. I installed a hydrogen peroxide pump and injector that activates with our well pump and is injected before the pressure tank. Then there's a catalytic carbon backwashing filter that filters out the iron and manganese, then goes to a water softener. The filter was the best investment I could have made and I shouldn't have hesitated so long to get it. I just had our treated water tested again and the Iron was not detected, manganese was not detected. Went with a stenner pump to meter the H2O2. Best investment ever. I was battling the iron and using the water softener for it, but knew that was a bad idea.

 

[Mswlogo]

Water Softener is in and Manganese is now 0 ppm

It’s 1.5 cu ft. Of Resin.

I set it to

9lbs for 30,000 grains (6lbs per Cu ft)
Hardness I set to 8 (rounded up from a little over 7. My hardness is 3.7 with Manganese at 0.5 ppm.

It reported regen every 3600 gallons. But I also set it to not go over 28 days. Which I suspect I’ll hit long before using that many gallons that’s 3x our usage). Might use a lot more water in summer.

I have a 2.2 gpm restrictor in there for backwash. I forgot to measure actual gpm before crimping it in. But it rose resin almost to the top on backwash. You can see the filter vs backwash height markers on the tanks.

I plan to use Potasium Chloride and expect to use 3 bags a year. $100.00

Filox should last decades (asumming nothing breaks) and Resin probably at least 10 years.

 

[Taylorjm]

So I'm guessing the first tank is the backwashing filter you mentioned, but did you change anything to help with the iron issue? H2O2 injection or anything? I see the spin down filter is orange, so you have quite a bit of iron, but you don't seem to have any kind of sediment filter before the backwashing filter or softener. The spin down will only capture large particles and having the sediment filters after the backwashing and softener seems a bit backwards to me.

 

[Mswlogo]

So I'm guessing the first tank is the backwashing filter you mentioned, but did you change anything to help with the iron issue? H2O2 injection or anything? I see the spin down filter is orange, so you have quite a bit of iron, but you don't seem to have any kind of sediment filter before the backwashing filter or softener. The spin down will only capture large particles and having the sediment filters after the backwashing and softener seems a bit backwards to me.

The First filter is a 1.5 cu ft Filox. It’s doing a good job getting rid of all the iron. But their might have been a trace getting through. That’s partly why I didn’t want to mess with that. We have 7.7 ppm Iron (but I think it varies seasonally).

Since pH was 7.0 Filox didn’t get the Manganese.

So no air injection, no chemical injection.

Some chemical injections cause hardness to go up and you need a softener any way.

The air injection would not have enough contact time on high flow use cases (shower laundry etc. ). You’d need a tank.

One thing I’m bummed about though is Potasium Chloride isn’t great for the environment either. I live on a lake.