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Related FAQs: Water Quality and the Aquarium Garden,

/The Aquarium Gardener Series

Wa Wa - Water Quality

by Bob Fenner

Eclipse 12, Easy to Maintain

For pet-fish types the term "Water Quality" ranks right up there with the concepts of love, truth and beauty>. Just what is water quality? What the heck is just water?!

This is the introductory survey article in a series on the most popular and unpopular aspects of water chemistry and physics (Yikes!) as they relate to aquatic life. Abandon all hope (of ignorance and apathy) all ye who enter here.

First of all, if you know all this stuff already, read on anyway. After a zillion years in the pet fish industry (& hobby), twelve years O' Higher Edumacation (college) and a stint as a high school science teacher (I paid my debt to society), I've become, at least in my humble self-assessment, a wiz at explaining/massaging folks into workable understandings of the following facts, ideas, methods and attitudes. Some run-on sentence now!

Think of how you'll be able in turn to thrill and amaze (ex)friends and associates! So enjoy! & you're welcome.

What does it Matter??

Most all of us are familiar with the basics of what matter is> (has mass, occupies space); that such stuff along with energy and space up everything. Interaction amongst these manifests itself in the notion of time. Sub-atomic particles like neutrons, protons, electrons and even further sub-divisions make up basic building blocks (=elements, because they're so elementary) we call atoms. We label the various types of atoms on the basis of the number of protons each is made up with in it's nucleus and arrange our knowledge of kinds of atom in sundry Periodic Tables according to their relative behavior.

Wa Wa:

Most of just water is made up of the simplest element, Hydrogen (geez, the word itself means "making water!"); signified by the symbol H. Each hydrogen atom consists of just one proton and one electron (with no neutrons). The way things work out, single atom Hydrogen is not "happy" with a single electron in it's cloud/shell (an average area/space about the nucleus) & so typically we find most hydrogen as H2, or two hydrogen atoms making up diatomic molecules. You with me so far? Easy stuff.

Oxygen is the eighth element (the type of atoms with that atomic number/number of protons). That's right; with each atom having eight protons, most with 8 neutrons (varying numbers of neutrons per atom we call isotopes). Turns out the next "happy condition" or state for chemical species after "filling up" their innermost electron cloud/shell with two electrons is to have a more stable eight electrons in their next outer electron cloud/shell. And, yep, you guessed it; under conditions of temperature, pressure, et al., hydrogen and oxygen get together in the all-so-familiar ratio of two to one to "form", Ta Da!, H2O.

Now get this, H two Oh is not all that stable... under various chemical/physical influences it "falls apart" and "gets back together" as H+ (hydrogen ions; ionic or "charged" hydrogen), ripped off to some degree for it's negatively-charged electron and therefore positively charged. The remainder of the dis-associated water molecule, the negatively charged OH- or Hydroxyl ions are left similarly charged up, but negatively from getting that "extra" electron. There's even stuff like tritium, H3, deuterium H2 (shades of heavy water in nuclear reactors!),H2OO2 (Hydrogen per oxide; makes sense, huh?), and even other strange and exotic combo.s.

Before getting onto what all this means to you in keeping fish et al., allow me to visit with you regarding a few other weird things about this molecule we call H2O.

Hybridization, Whaaaaat?:

The spatial arrangement of Hydrogen & Oxygen atoms in water accounts for many of it's amazing (to me) & trippy behaviors/qualities>. Such as floating (becoming less dense as a solid versus a liquid), being the "universal solvent" (having more substances being more soluble in it than any other material), transmissibility of "light", sound, electricity, exceptional heat capacity... &, &, & other properties.

Water molecules are held together and apart by stealing (ionic) and sharing (covalent) bonding. The average angle/arrangement (105 degrees) is used to explain it's ability to seperate and squeeze in-between (dissolve, dilute) other materials. I won't belabor this point any further, but if the fact that water is SP3 hybridized, in it's arrangement of component parts and changes intrigues you, look into a basic entry level chemistry text, or through the citations at this piece's end.

This stuff is neat! & really bizarre and absolutely essential. Without water there is no life. Even for us, there is no gas exchange in our lungs without it, no smell or taste without chemicals dissolving in water in our nasal and buccal cavities. Water bathes our cells, makes up most of our cells, is the transport medium of food, wastes, reproduction... Why is there so much "free" liquid water on this planet anyhow? Well thank goodness there is> Oh anyway, back to fish.

What Else? It's in the Water:

Other stuff found in water is classified in various ways. Materials that are suspended in water without giving/taking of electron interactions we term particulates. Other matter with those chemical bonds let's call dissolved or in solution (or for extra bonus points, dissolved in aqueous (H2O solution). Ho-boy.

What are these solutes? Solids, gases, liquids that are to lesser and greater degrees miscible/soluble in the "body" of water in question.

These materials are what allow aquatic life; they make-up & stabilize pH (alkalinity, acidity), dissolved gases, redox potential, specific gravity, conductivity... matters of water chemistry/physics. I'm going to empower you to know these qualities, their importance and how to manipulate them. Next: The Wonderful World of Water Part II: pH, Alkalinity, Acidity & You!


Has my brief discussion "wetted" your appetite for further delving? For a tasteless, odorless, colorless (blue in thick layers), incredibly reactive in facilitating other chemical/physical reactions and yet amazingly inert-itself molecule, water is vital (makes up 70-80% of the weight of non-fat tissue cells of all vertebrates, including fishes and ourselves), allowing the processes we call "life". Oh, and yes, providing us with this spiffy hobby.

The first piece of recorded writing, in Linear B Greek, transliterates as "All is Water". Truer words cannot be written.


Horne, R.A. (editor): Water and Aqueous Solutions; Structure, Thermodynamics and Transport Processes. Wiley, New York. 1972.

Parry, Robert W. et al. Chemistry, Experimental Foundations. Prentice-Hall, New Jersey, 1975 and later eds. Symposia of the Society for Experimental Biology, No. 19, "The State and Movement of Water in Living Organisms. Academic, New York, 1967.

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