Sorry, but you don't have clue what you are talking about. Seawater has a maximum Bc at a
pH of 6 & 9, as that is what its pKa is, so if the pH was 9 it would have the greatest
ability to withstand a pH shift, as half of the principal buffer is HCO3- and half is
CO3--. The HCO3- acts as the acid and CO3-- is the base.

At any pH there is an exact ratio of CO2 + H20 : H2CO3 : HCO3 : CO3. As soon as RO/DI
water is exposed to air it will pick up CO2 and the pH will fall, the Alk will remain the
same. Below is how mixed bed resins work

http://rip1.wwwcomm.com/resintech/Co...ell%2089-2.pdf


"Therefore the constant addition of
alkaline water which you trust to be pure DI water, and it no longer is,
slowly eats away at the tanks buffering capacity. Once the last of the
buffering salts covert to their basic form, the buffering is gone and the PH
starts creeping up."

Lets be short, explain that in chemical terms and show any ref that states that from
chemical stand point.You won't find one will you. We are always adding basic ion's, such
OH- and is the reason behind adding kalk, Ca(OH)2 so the so called additon would be plus.

Once the RO/DI water is exposed to air and once a seawater mix is added that water it is
buffered and has a pH, what ever it is and a buffering capacity and if it sits its
buffering doesn't change over time by magic.Finally, in a working seawater aquarium the pH
and "buffering capacity" are always working to the down side, low pH and low Alk unless
you add supplements to counter-react it.

"I'm sorry but I've seen it happen on a very large scale where a plating tank
was destroyed because the DI water automatic top-off shifted the PH of the
tank."

That is because you don't understand water chemistry, you are assuming and guessing. You
may want to look up some ref on plating water chemistry, there is tons out there.

Here is a BIG start on reef water chemistry

http://reefcentral.com/forums/showth...hreadid=102605

If you can't see this go here

http://www.advancedaquarist.com/issues/may2002/chem.htm


I have been in this hobby for over 30 years. Most of my post on NG's and internet boards
( see link below) are on water chemistry and I have yet seen any such thing as you claim.
That is because there is no such thing as you claim.....sorry. Feel free to come to our
chem. forum and post what you have said and see what kind of answers you get. I am not a
chemist, although many label me as one. There are a number of chemists on our board with
Ph D's in chemistry. The most well know is on the link above and moderates our forum on
the link below. All see the post on this NG to Tre'

--
Boomer

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

Want to See More ?
Please Join Our Growing Membership
www.coralrealm.com

If You See Me Running You Better Catch-Up