tritration of alk to achieve a desired ph

[squirrelieygrrrl]

chemists,

 

i am trying to find out if there is a way to tritrate sea water in order to achieve a desired ph level. from my understanding about the alk acid base balance, one should be able to add a base or acid to tritrate the alk in order to raise or lower the ph. my question is; is there a formula for how much base to add to achieve a desired ph to counter act the effects of the alk as a buffer? i understand how to tritrate sea water with an acid to the end point of the buffering capacity, is about 2.5 meq/l the value for sea waters alkalinity. how ever can this formula be applied for adding a base to tritrate the sea water on the opposite side of the scale? here is yet one more idea; if respired c02 is removed almost as qucikly as it is produced, the tank will remain in equilibrium, and there will be no net change in the ph. on the other hand if carbonate and bicarbonate ions are being removed from the aquarium via photosynthesis the ph may rise according to this equation in reverse : C02 +H20 = H2C03 = Hc03- +H+. any chemists out there that understand this process and can explain it to me further and how to correct my low ph would be greatly appreciated! i am at a loss

 

~one squirreliey grrl

[squirrelieygrrrl]

some of the information is cited from water chemistry for the marine aquarium by john h tullock

[yardboy]

If you have sufficient alkalinity and your pH is elevated, you need to determine why the pH is low so you can cater your actions to the cause. Because seawater is buffered with several different compounds in different ratios, and you are limited in what chemicals you can add to raise the pH and have it have a lasting effect.

Before I say too much more, look at this article which will explain it far better than I can.

[squirrelieygrrrl]

thank you yardboy,

 

that article was very informative.