Article question.

[SeanT]

Hi Randy,

In your latest article, entitled Reef Aquarium Water Parameters, it states in Table 1 you state that the "Typical Surface Ocean Value" of Alkalinity is 7.0 dKh.
At first that didn't jive in my brain as I have always read that the Alkalinity level of NSW was 8.3 dKh.

Over the past 6 months I have been using filtered NSW from the University here and it's Alkalinity is also 7.0 dKh.

My questions are;
1. Where did you get the info on the 7.0 dKh?
2. Are the Alkalinity levels around the reefs in the Pacific Ocean higher?
3. If not, why should we shoot for a higher Alkalinity level in our tanks? Better growth, color? But does it stress the coral as well?
4. Is there anything detrimental about keeping an SPS tank at an Alkalinity of 7.0 dKh?

Thanks,
Sean

 

[Randy Holmes-Farley]

The chemical oceanography texts (Chemical Oceanography by Frank Millero, for example) that I have, and most references that I've seen give an alkalinity in the low 2's of meq/L, or about 7 dKH.

Folks sometimes shoot for higher alkalinity because it leads to more pH stability, higher pH if low pH is a problem, and to more rapid calcification in some corals.

I am not familiar with any concerns with respect to corals and reasonably high alkalinity as long as calcium and pH are OK.

 

[SeanT]

Hi Randy,
Thanks for the response.
Does the "references that I've seen give an alkalinity in the low 2's of meq/L, or about 7 dKH" include around the reefs?
I assume it would but am just curious.
Sean

 

[Randy Holmes-Farley]

It is supposed to be largely the same the world over.