Tex Gal

Ray-the-pilot I only wanted to see the pictures because it fascinates me to see the little guys! I have trouble taking pxs of my tank with the plants - forget about the swimming fish - much less teeny tiny ones! The best I've done with egg layers is danios and kribs. My pxs leave a lot to be desired!

Sounds like you've been doing fish as long or longer than I have. Of course, I'm not the chemist so I still don't get the water thing. I do the best I can.... Acid? Alkalinity? Buffering agent??? .... and how does the CO2 REALLY bring the pH down?..... (ok.... I'm getting a headache now!)

If you were talking about my tank - thanks for the kind words. I take it as high praise from someone as experienced as yourself.

 

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ray-the-pilot

I misinterpreted your signature as a comment on my post. That set me off on my previous experience post. After seeing today’s post I realize my stupidity. Sorry about that.

And your tanks do look very nice.

Zapins

Hey, Tex just noticed you mentioned CO2/pH etc... and how does it all work?

All an acid is is simply a substance that releases H+ atoms into a liquid. Any substance that gives off H+ atoms (or more properly called ions - due to the lack of an electron that makes it positively charged). There are many kinds of acids as you can imagine. Carbon dioxide lowers the pH (pH is the unit for measuring how much H+ atoms are in a solution) by combining with water and releasing H+ ions.

The reaction goes like this:
H2O + CO2 <--> H2CO3 <--> H(+) + HCO3(-) <--> 2H(+) + HCO3(2-)

Water reacts with carbon dioxide (CO2) reversibly making carbonic acid (H2CO3) (this means that carbonic acid can also break apart and make CO2 and H2O). The carbonic acid then reacts further and breaks apart releasing some H(+) ions. Carbonic acid is diprotic so both hydrogen atoms attached to the carbonic acid can dissociate (split off the molecule) making 2 free floating molecules of H(+) and a molecule of CO3(2-). These reactions all bounce back and forth reacting and un-reacting until the CO2 gas finds its way to the surface of the water and leaves the water, or until the H+ ions are trapped by binding to something else (like a buffer or base). When this happens the reactions outlined above can't take place in the water and the pH rises because there are no more H(+) ions being made. This is why pH drops when more CO2 is added and why it goes up when CO2 is lost.

Since acids are essentially molecules that release H+ ions into a solution bases do the opposite, pulling H+ ions out the water. A base is really any molecule that accepts H+ ions.

Buffers are molecules that change the pH of the solution (absorb or release H+ ions until a desired level is reached). Buffers usually are molecules that contain both H+ releasing areas and H+ accepting areas (in other words buffers are both acids and bases at the same time).

Alkalinity is basically a measure of how much buffering capacity the water has. In other words it measures the amount of all buffers in the water. So in the practical world if you have a low alkalinity then the water's pH will change quickly and be unstable if an acid or base is added to the water. This is because the amount of buffering chemicals in the water is too small to fully neutralize the acid or base that was just added.

ray-the-pilot

I guess I must have clicked somewhere I wasn’t supposed to? My post above seems to have disappeared.

I misinterpreted your signature as a comment on my first post. So I went into my experience post. When I read your answer, I realized my mistake. Anyway I wanted to apologize for that pompous post.

Also your tanks are very nice!

 

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