05-28-2010, 07:16 AM
| || |
Originally Posted by Byron
It would seem that you have a considerable amount of dissolved carbon dioxide (CO2) in your well water. This often occurs in tap water too, which is why it is recommended to let tap water sit for 24 hours before testing the pH, as this gives the CO2 the time to dissipate from the water. CO2 lowers pH because it is adding acid, and when it dissipates from the water the pH rises. This is the same in reverse as when planted tank aquarists add diffused CO2 to their tanks, it lowers the pH.
Sometimes objects in the tank that are calcareous (rock or gravel made from calcareous rock, coral, dolomite, marble, lava, etc) are the culprits but in this case you have tested the water on its own, so I suspect the CO2 is the answer.
Thanks for the great information Byron. I was wondering what was happening. So even after I let my water sit for a week and add it to my tank when it's around 7.2, it still has enough CO2 to dissipate to raise my pH to 7.8? Or is the CO2 already dissipated? I was just hopping it was all the marble river rocks that was raising my pH.
If the CO2 is the culprit, what can I do about it? Would a product like Seachem's Neutral Regulator work for me? It was recommend by my LFS. It is supposed to adjust the pH to 7.0 and keep it there.