Question to Randy

[yraveh]

Hello Randy,

I was reading your article "CHEMISTRY AND THE AQUARIUM " at: http://www.advancedaquarist.com/issues/feb2002/chemistry.htm
It is excellent! it has clarified a lot of confusion for me.
thank you.

please allow me a few questions/comments
1. at the section "Step by Step Acidification" you included H2co3 as a proton acceptor (although a minor one, in black coloring). It is however identical to adding CO2 which does not change alkalinity!
2. In medicine we use the term buffer (in blood) which is exactly identical to "alkalinity" but less confusing. isn't "alkalinity a misnomer"
3. In blood chemistry we measure the "base deficit" or base excess. That would have been the most practical terms to use in reef
4. I am puzzled about the frequent warning not to use distilled water to compensate for evaporatory loss. Why not? if you loose water >>why not correct with water?

thank you

[bertoni]

Distilled water is often fine to use for topoff, but some brands get a bit contaminated on the way to the end user. I've measured some that wasn't all that clean. RO-DI is safer, in my estimation. Distilled water is also too costly for most setups.

[Randy Holmes-Farley]

1. All of the ions listed on the far left of each line (H2CO3, Mg++, B(OH)3, Si(OH)4, etc) are not proton acceptors. They are the resulting product of adding H+ to the compound just to the right of them. In that case, bicarbonate. :)

In medicine we use the term buffer (in blood) which is exactly identical to "alkalinity" but less confusing. isn't "alkalinity a misnomer"


Definitely not. Alkalinity has a specific definition that is very different than buffer. Water can have high alkalinity and little buffering, or high buffering and little alkalinity.

I discuss buffering in this article:

Boron in a Reef Tank (and its effect on pH buffering)
http://www.advancedaquarist.com/issues/dec2002/chem.htm

[yraveh]

Thank you

[Randy Holmes-Farley]

You're welcome.

If you have any other questions, just pop back. :)

Happy reefing!