Water is everywhere – and everything is water. But how well do you know its fundamentals?

Let’s explore in detail the base ingredient of our Water Industry!


1. What Color is Water?

Is a child right to give water its characteristic blue color in any drawings? Well, absolutely! Water is really blue.

That may be hard to believe when you’re watching it in a glass, but it starts to reveal as soon as you have larger quantities – for instance, in a one-meter transparent pipe.

Water’s color in its liquid phase and the visible range is due to hydrogen bonding. Indeed, as it absorbs red wavelength at multiple harmonics, it, in turn, shifts the spectrum towards blue.

Now, there’s an exception to that rule, which you probably noticed if you’re working in advanced physics fields such as nuclear magnetic resonance or infrared spectroscopy.

(In which case it is also fair to assume you did not wait for me to know the color of water)

Heavy water, that features deuterium or heavy hydrogen instead of the regular hydrogen atoms, is colorless in the visible spectrum.

So, it’s an excellent way to rapidly check if your neighbor is secretly preparing a nuclear bomb in its basement. Just measure the color of his water!

Now, beyond that (kind of) exceptional case, water’s color can also give more hints at its quality or characteristics.

2. What Color indicates Safe Water?

That one is actually tricky.

I’m sure you’ve already had some tea: that’s colorful water, yet still a safe one.

Indeed, if colorless water is considered pure, it could still be unsafe for human health. And if colorful water certainly indicates that something is dissolved or in suspension inside, it may still be suitable for consumption – aka safe.

Now, color nevertheless gives a hint at what’s inside. Dissolved organic matter will turn the water blue or brown, while most algae turn it green, and soil runoffs make it yellow, red, brown, or gray.

Hence, if color can’t tell if water is really safe, it can be a good surveying tool for biological monitoring.

For instance, a satellite survey of 1486 lakes in New Zealand revealed their quality shape – and allowed following that shape over time.

I wonder what those satellites would think of that water:

3. Why does Water expand when it freezes?

Water is quite of a contrarian.

For most of the earth’s matters, they vibrate and move around when they’re hot. So they take some space.

But when you cool them down, they suddenly become much more docile, stop moving around and hence shrink a bit.

What about that water punk? Well, when it vibrates and moves around, it’s happy to restrain its social distancing. But if it has to stay in place, nicely aligned in an ice shape, it prefers to keep its distance from its neighbors!

This has, of course, an atomic explanation: oxygen atoms are slightly negative while hydrogen ones are positively charged. So, they stack up according to their charges.

But isn’t the water-punk explanation even cooler?

Why is ice less dense than water?

Let’s imagine we have one liter of water. That water, being liquid, weighs one kilogram and fits in a cube with 10 cm edges.

Now, as we’ve seen, water expands when it freezes. But how much?
Actually, it would now take a cube with 10.29 cm edges!

But of course, it would still weigh one kilogram.

So, if we do the maths, 10.29 cm edges for our cube make for 1’088 cm3. With 1000 grams fitting inside, that provides us with a density of 1000/1088 = 0.919

As liquid water has a density of 1, we see that ice is indeed less dense than water. All because of this expansion when water freezes!

Why does ice float in liquid water?

That one shall now be logical, right? Despite its punk nature, water doesn’t breach all rules of physics.

So, when the ice that has a lower density finds itself mixed with liquid water (which has a higher density), it floats on top.

4. What is brackish water?

Coming from the Dutch term “brak,” brackish water defines a salinity level above freshwater yet below seawater.

Typically, that’s the water you’ll find around estuaries where rivers (freshwater) meet the sea (salt water).

What is brackish water’s salinity?

When it comes to salinity, we consider water to be fresh up to 0.5 parts per thousand (ppt).

(Fun fact: as soon as it exceeds 0.1 ppt it is no longer potable.)

Brackish then ranges from 0.5 ppt to 30 ppt, and seawater from 30 to 50 ppt (beyond, it’s considered brine).

Wanna brag with some more fun facts at your next dinner in town? The limit for agricultural uses of brackish water is at 2 ppt of salinity.

And while the average seawater is saline and measured at 34.7 ppt, some seas are still brackish. For instance, the Black Sea has a salinity of 18, while the Baltic Sea is as low as 8.

And don’t take it with a pinch of salt: those are facts.

5. What does water taste like?

Answering this question involves, having mice licking light. Don’t freak out, I’m not yet fully mad, and you’ll see that this sentence ends up making sense!

So, to start with, let me disappoint you: water tastes… like water.

The news here is that water actually has a taste and that it arguably is the sixth one, next to sweet, sour, salty, bitter, and umami. That’s what Caltech University researchers found out, by studying mice at least.

Now, to qualify that taste, they stimulated the mice’s taste sensors. The idea was, that when they’d hit the right one, the tested animals would be wanting to lick whatever stimulus they were receiving.

And, as I spoiled you seconds ago, they ended up stimulating the mice’s sour sensors with specific blue light, resulting in them trying to lick that light to “drink” it.

So water tastes like water, and that taste is close enough to sour to use the same sensors. And the next time you’re really thirsty, out of water, and want to trick your brain, you can try to have some blue light instead!

6. How to make distilled water?

Step 1: wait for rain. Step 2: collect rainwater. Step 3: profit.

Ok, that was maybe troll physics, it nevertheless is kind of true! Distilled water is water that went back and forth the steam transformation. So, it evaporated and condensed again.

And what is rainwater? Well, if you’ve been listening at school when tackling the Water Cycle, you know that it is water that evaporated and now condenses.

There’s nevertheless a bit of caution to take here, because that water has traveled a bit, before raining down. And it can have dissolved some stuff on the way, which makes it sort of polluted distilled water. So to be on the safe side, you’d better reproduce the cycle yourself in a controlled environment.

But that’s nothing you can’t do with water, heat, and cold sources.

Feel the power of the Water Cycle! (even on small scale)

What is the pH of distilled water?

That’s straightforward: it’s the beautiful theoretical value for water: 7. Nicely in the middle, neither basic nor acidic!

Well, at least, seconds after distilled, because if you wait a bit, and assuming you’re not producing distilled water in a vacuum, it will react with ambient air, and more specifically its CO2. That bonding will produce small amounts of carbonic acid, until reaching an equilibrium point of 6.

So, in the longer run, the pH of distilled water is slightly acidic, and hovers around 6!

Can distilled water kill you, if you drink it?

Here’s the fear. Distilled water is mineral-free, by definition: it’s pure water. So, if you get to drink it, it will start dissolving your body’s minerals, until a point where it starts affecting your equilibrium. And in the long run, it kind of kills you from the inside.

That makes about sense. Except, that it’s not true!

Let’s compare distilled water with drinking water, that’s reassuringly full of minerals: at max, you’re talking of 200 ppm of total minerals (if not, it wouldn’t be potable). So, if your tap water was at the maximum possible, it would contain 200 ppm of Na, K, Ca and Mg combined.

Let’s assume, that you’re drinking the recommended quantity per day of 8 glasses, which makes for 400 mg of minerals. Meanwhile, the recommended daily quantity of minerals is 7g. So, unless you’re starving or eat very unhealthy, one can assume, that a good portion of this 7g (aka, at least 95%) is coming from whatever you eat!

So, it won’t change much – or sufficiently to be noticed – if you started drinking only distilled water.

And what about the acidic pH, you ask? Well, try dying from drinking Coca Cola, then. Its pH is 2.7, and pH is a logarithmic scale. So it’s at least 1000x more acid than your distilled water.

And what if you don’t eat, and hence don’t get your minerals from food? I’d say, you would still die from something else than distilled water, wouldn’t you? 😅

7. How to make water?

So, what is water again? Well, dihydrogen monoxide. You’re right, it’s not convenient to call it like that, but it hints at how to produce it!

Indeed, all you need is hydrogen and oxygen gases, mix them up and give them a gentle kick to get them started. As a result, you’ll get water and a bit more energy than what you brought into the system, kind of a win-win!

The only drawback, of course, is that this “gentle kick” tends to look like an explosion. So, the more water you intend to produce that way, the bigger the explosion. For instance, the Hindenburg exploding upon arrival in New Jersey in 1937 might have killed 36 people, but it also produced a bit of water.

(yeah, even I wouldn’t call that a “win” of any kind)

Now, there’s another way to make water, and it may well be what Earth did, some million years ago. You “simply” need a bit of magnesium hydrosilicate (Mg2SiO5H2), and reduce the pressure on it, until it releases the H2O it contains.

Ok, I may have taken a zillion shortcuts here, but you anyways have a bigger problem at hand if you want to use this technique: today, magnesium hydrosilicate doesn’t exist on earth anymore.

You have a last solution left: make water as Mars does. Simply wait for an asteroid to crash nearby, and collect the water it contains! It might be slow and hard to control, but are you really thirsty?

8. How many hydrogen atoms are in a molecule of water?

Ok, let me confess that one is obvious. We’ve already widely covered it, water is H2O, hence has two hydrogen atoms per molecule.

Now still, that might depend on the phase of water we’re talking about – if you allow my pickiness. Because as Gerald Pollack told me on my podcast microphone, in its 4th phase, water may rather be called “H3O2.”

In which case, you would have 3 hydrogen atoms per molecule! Checkmate, captain obvious.

9. Is water wet?

Another tricky one, right? A solid is wet when a liquid adheres to its surface. So, can a liquid be wet? By definition, no.

Let’s dig further. Wetness is at the end of the day a fight between cohesive and adhesive forces. Cohesive forces bring a liquid together, that’s the liquid-liquid relationship. Adhesive forces on the other hand spread a liquid over a surface, that’s the solid-liquid relationship.

Hence, if the adhesive forces win, a solid ends up being wet (liquid adheres to its surface).

… and if it’s the cohesive forces, then the solid stays dry as the liquid doesn’t bond with it.

Generally speaking, cohesive forces are quite strong in water, which makes it much less of a “wetting” matter than alcohols or acetone. (by the way, this is caused by the hydrogen bond)

So, water is quite rarely causing a solid to be wet – but still does, for instance with glass. And water certainly doesn’t wet itself, simply by the definition of it.

Would you like a paracetamol tab before we continue?

If water is not wet, what is it?

Ok, now, let’s review our definition of “wet.”

If wet is the sensation that you get when you touch a liquid, then, water is wet to us. And if “wet” means “made of liquid or moisture” then it’s even more straightforward, water is wet.

So maybe I should stop playing with words, and move to the next little badass secret about water?

10. How to make holy water?

That one is counter-intuitive! In fact, making holy water doesn’t start with water but… with salt!

  1. Make “Holy Salt”

    You’ll need your salt to be as pure as possible (for instance, natural rock salt). You’ll then bless it, by following the Roman Ritual. Interesting enough, the procedure is slightly different, depending on if you’re doing it all alone, or if someone joins in (in which case, you’ll have one more prayer to tell)

  2. Get some water

    For god’s sake (pun intended 😅), don’t take it from a tap! Tap water may be the perfect drinking water, but it contains chlorine, which you don’t want to feature in your holy water. So get water from a river or a lake, and make sure to filter it. (If not, you’ll be making dirty holy water.)
    Still, avoid drinking it when done: it may look clean but not be potable.

  3. Exorcise that water

    You’ll have another prayer from the Roman Ritual to tell out loud, plus a bonus one if you’re in front of witnesses (that shall join in)

  4. Pour the Holy Salt into the Exorcised Water

    … and do it in the shape of a cross. Plus, of course, recite the right prayer at that moment in time (and offer your witnesses to join in)

  5. Bless the water

    Now, you’ll have to pick a prayer from the Book of Blessings, and say it out loud in front of your holy water. When done, make the sign of the cross over the water.

  6. Use your holy water!

    You can use it to bless your home, your family…

… or fight some demons!

11. What is potable water?

Potable and drinking water are the same: it is – literally – water that’s safe to drink. That being said, it is also a matter of regulation and compliance: every country or regulatory body defines what potable water actually stands for.

The world health organization sets a standard, that many follow, but some countries walk the extra mile and put more stringent limits on chemicals, substances, viruses, or bacteria.

By the way, let’s note that mineral water is generally potable, but not always. So you might be buying bottled water while doing your groceries, and still not bringing potable water back home.

12. What is the healthiest water to drink?

Here, we’ll have to cut through the fog. Every mineral water brand or spring water supplier will tell you how, given the place where it comes from or the portion of earth it crossed, it probably is the healthiest water to drink.

And if I was one of these bloggers, I’d probably insert here some affiliate links to my favorite water brand – or the one that gives me the best payback. (As I won’t do that, I’ll send you instead to my deep dive that explores the risk of letting bottled water take over)

So, if that propaganda is not true, what is? Well, if you’re providing your body with sufficient amounts of water proven to be potable, that’s for sure the healthiest. It’s still not a given in a world that hasn’t completed its route towards UN SDG 6, but sometimes simple rules are the right ones.

In summary, you’ll want potable water, that hasn’t stayed too long in your piping system. And you’ll want your piping system to be modern enough, to not contaminate your water. Simple!

13. Could Icebergs become Sustainable Sources of Drinking Water?

In 2030, the World will miss 40% of the water needed, to accommodate all our needs. Hence, it may become wise to be creative and to look at alternative water resources.

That encompasses cloud nets, atmospheric water generation, wastewater reuse, and… Iceberg harvesting. Sounds crazy right? It even sounds wrong: isn’t that just direct exploitation of global warming?

Well, not really. Icebergs are created and melted every year in Antarctica, with the simple play of seasons. Sure, global warming probably also has an influence there, but Icebergs are really a drop in an ocean of ice there when compared with sea and earth ice.

Hence this crazy Idea: reaping these Icebergs, which are one way or the other due to melting, and turn them into drinking water resources for the arid places of this world.

That Idea is not new, it’s been around since the early 19th century!

But is it a good one? We review the crazy Idea of towing Icebergs around in detail right here.

Spoiler: it may be much less insane than it first sounds!

14. What type of bond is water?

15. What is water made of?

16. Why is water called the universal solvent?

17. Where does water come from?

18. How to float in water?

19. What is the freezing point of Water in Celsius?

20. What is black water?

21. What is grey water?

22. What is hard water?

And what is soft water?

23. How many calories does water have?

24. What is the energy source for the Water Cycle?

25. Why is ocean water salty?

26. What causes water to break?

27. What percent of your body is water?

BONUS: What’s to expect from 2022?

Hey Water Industry: Nostradamus Called! What’s to Expect from 2022?

🙋 What will happen next year in the Water Industry?

Together with Björn, we took 10 bets for 2022!

Here are the two reasons to care about those predictions:

1️⃣ Wouldn’t you be better equipped to face the future, if you knew everything in advance? 💪
2️⃣ Wouldn’t you want to have a great reason to mock us when what we predicted doesn’t happen? 😀