operation oaxaca: america got hard.

an elongated problem: metal ions in our shower, USA (012)

Carlos Manuel Jarquín Sánchez
8 min readFeb 16, 2024

this is carlos.

now is the article i promised you.

my fuel stems from my village in oaxaca, mexico.

but i am also considering what’s going on in the united states.

and yes, there exists a problem or two.

not as bad as in oaxaca.

but somewhat disturbing.

and you don’t even know about it (most likely).

the mystery foe shall be revealed.


i assume u shower in the morning.

no point going to work/school like a skunk.

and yet, you still put shampoo on your head when you shower.

congrats, you got scammed.

nah, i ain’t no hacker.

but talk to your bath products.

the shampoo is meant to moisturize your hair.

but from what?

sweat, dirt, and pores?


but there’s something in the water.

and one drop of it can make your hair wrinkle up like old fruit.

it’s calcium and magnesium metal ions.

no way, u’re tripping… right?

but how does the calcium/magnesium get into our water?

it typically stems from limestone & dolomite.

limestone has a composition of calcium carbonate (CaCO3). so when it dissolves/mixes with water…

it will release calcium ions (Ca2+) into the groundwater/soil, and eventually into our drinking water systems.

cool, but how?

the chemistry part.

when rainwater interacts with carbon dioxide (CO2) in the air, it becomes somewhat acidic. (‘acidic’ means pH is lower than seven)

the chemistry of water is H2O. this is a liquid, so we use (l)

carbon dioxide is CO2. this is a gas, so we use (g)

combine them, and we get:

H2O (l) + CO2 (g) = H2CO3 (aq)

H2CO3 is carbonic acid.

“aq” means aqueous.

aqueous derives from the word “aqua”.

aqua is latin for water.

so this means if something is aqueous, the solvent is water.

solvent → the fluid/material that contains our molecule/solid.

(in our case, the solvent is our water, because H2O was needed to make our carbonic acid.)

anyways, H2CO3 will not bond together in water.

it will split into two separate molecules.

H2CO3 = (HCO3-) (aq) + (H+) (aq)

H2CO3 = bicarbonate ions + hydrogen ion

these ions are both anionic and cationic.

but when there are hydrogen ions in our water, this makes the water more acidic.

water becomes acidic when there are more H+ ions than OH- (hydroxide ions).

this is also the process for ocean acidification, but let’s focus onto homewater in usa.

this acidity from the hydrogen ions is still in our rainwater when it comes pouring onto the limestone.

but still… how does that acidic rainwater force calcium ions to come outta the limestone rock?

round two.

there will be another separation of molecules when the acidic rainwater makes contact with the calcium limestone.

the chemistry of the limestone rock is: CaCO3

and then is the acidic rainwater: H2CO3

but the acidic rainwater has been separated into H+ & HCO3- because of being surrounded by rainwater. (it’s the solvent, or fluid for our CO2 to remain in)…

and the chemical reaction between the limestone and the rainwater is:

CaCO3 + H2CO3 = (Ca2+) + (2(HCO3-))

Ca2+ → calcium ions

2(HCO3-) → bicarbonate ions

ok, but what happened?

remember, H2CO3 is also H+ & HCO3-… so we’ll re-write the equation:

(CaCO3) + (H+) + (HCO3-) = (Ca2+) + (2(HCO3-))

but this is only for one water molecule.

to get two extra protons, we would need two water molecules.

so the chemical equation should look like this:

Ca (s) + 2(H2O) (l) + CO2 (g) → Ca (s) + 2(H+) (aq) + 2(HCO3-) (aq) →

→ Ca2+ (aq) + (2(HCO3-)) (aq) (final)

…and that’s how we get calcium ions.

those two extra hydrogen ions would take the two outermost calcium electrons.

and create hydrogen atoms.

as for calcium…it lowers the energy of the electrons on the outermost shell.

brief explanation:

calcium has two electrons in its outermost shell.

each electron has energy, that affects the total element.

if we can get rid of “electron energy” that could lower the whole atom/element’s energy…

then the tendency of these outermost electrons will be to bond or remove them.

sry, i know the picture is too big lol.

so eliminating the outermost electrons will mean that there will be more positive charge than negative in the calcium ion.


the energy of the atom has lowered, as it no longer has to deal with such volatile “behavior”.

it’s like kids when they cry. (they behave like the two outermost electrons).

to lower their energy state, give them candy. (and it lowers their energy state, they’re calm now.)

and now, la.

you got to know the chemistry part of how calcium got into our water.

but u most likely live in the usa.

but you’re asking yourself.

“sure. but how much do i have in my water? and how much is considered bad? and what will it do to me?”

fair point.

i’ll use la, it’s what i know best.

according to the ladwp (department of water and power):

the la water hardness level is between 10–15 gpg or 171–257 ppm.

ppm → parts per million (1 atom/molecule for 1,000,000 of those molecules)

hardness level → how much calcium and magnesium in water, or calcium carbonate (CaCO3)

but what is considered okay?

these are the metrics:

0–60 mg/L is considered soft water.

61-120 mg/L is considered moderately hard water.

121–180 mg/L is considered hard water.

180+ mg/L is considered very hard water.

p.s. : mg/L is also ppm for aqueous solutions only.

domestic wells (for water collection) in united states
hard water (concentration of calcium carbonate) in water sources usa

cool, so what happens to the body when it comes into contact with calcium carbonate (hard water)?

for la, let’s go specific.

when you shower with the hard water:

the calcium/magnesium ions hair cuticles to rise, leading to hair that feels rough and dry, leading to hair loss.

the cuticles are like a protective barrier around the inner layers of the hair.

so when metal ions come in contact with the hair, it can be affected via:

  • moisture absorption interference
  • mineral deposits
  • pH imbalance
  • reduced lathering

the quick fix?

just use a chrome faucet or a showerhead.

but then you must remove the metal ions.

how tho?

your household hero.

believe it or not, you just used it last week.

your antidote to metal ions is in your kitchen,

most likely in a glass bottle.

it’s vinegar.

more specifically, white vinegar.

and lemon juice.


vinegar contains acetic acid.

lemon juice contains citric acid.

the chemical structure is:

  • CH3COOH (acetic acid)
  • C6H8O7 (citric acid)

in acetic acid, there’s one carboxyl group (COOH).

in citric acid, there’s three carboxyl groups.

citric acid, notice the 3 (COOH) groups?
acetic acid, see the COOH group?

these carboxyl groups have anionic tendencies due to:

  • electronegativity, of carbon (2.5) and oxygen (3.44) using the pauling scale… 3.44 - 2.5 = 0.94, a polar molecule, so more electronegativity will go to the oxygen molecule.
  • ^this also includes oxygen (3.44) & hydrogen (2.1)… so 3.44 - 2.1 = 1.34, also polar, so oxygen wins the tug-of-war (in terms of where the electrons may be located.)
  • sometimes, resonance too plays in the mix. because both oxygen atoms won their tug-of-war over the electrons, oxygens has the negative charge in the carboxyl group.
  • ^but because the charge is not on one atom only, (it’s on both oxygen atoms), we say the charge is delocalized. it’s not fixed on one separate atom/element.
  • ^but this makes the negative charge even stronger. the charge will “spread like pb&j” between the two oxygen atoms.

but the most important one will be when the acetic acid and nitric acid mix with the water from the shower.

when carboxyl groups come into contact with water molecules, there will be hydrogen bonding between the (COOH) group and the water molecule (which is made of hydrogen bonding).

this attraction is strong enough to remove & release a proton from the COOH group into the water.

the COOH group becomes:

COOH = (COO-) + (H+)

COO- = carboxylate anion

H+ = hydrogen ion, proton

and this makes our acetic acid & nitric acid anionic… the carboxylate anion (our main structure) is negatively charged!

and metal ions are cationic.

so that means they can be adsorbed from the peel!

legendary move, mother nature.

the H3O+ is the water molecule (H2O) and the released hydrogen ion (H+) into one.

ok, so what?

here is why i care about telling you about this:

the calcium/magnesium issue is not a danger to human health.

but these are valuable minerals that could become used as, supplements, for example.

think of how much value we put down the sink.

and the way to remove metal ions at an economical cost…

you definitely used them last week in your food!

vinegar. lemon. duh…

all these pieces, including mango peels, all of them are used in mexico!

and usa!

damn me.

this can tell us more about if we have a potential solution to the current way of filtering ions from water…

and not just the ones in your shower…

but the ones that contaminate the water for millions of people.

we’ll speak more about the economics of chemical precipitation, for regular filtration.

what is the status quo of how we currently filter ions?

why does vinegar/lemon juice work, economically & chemically?

do industrial processes use ion-exchange, chelation, or something else? how do they work?

and how do we “recycle” the ions in typical industrial processes?

© 2024–2100 by Carlos Manuel Jarquín Sánchez. All Rights Reserved.