2 Question for Randy

[Shadowramy]

Randy,

First off, you have some great articles that I find fascinating!! I have a couple of questions that I would like to ask. These are in reference to your “When Do Calcium and Alkalinity Demand Not Exactly Balance� article.

In your article you state that magnesium is taken in roughly 1%-4% by corals depending on the species. Do we know yet which species might take up more magnesium and which ones take less?

Second, in your article, you state that the interruption (for lack of a better word) of the nitrogen cycle can deplete alkalinity (especially through water changes). I was wondering what effect this interruption might play in a low nutrient system such as a ZeoVit system where Ammonia is essentially being "locked up"? Would these systems tend to be more on the low alkalinity side naturally causing long-term issues by becoming unbalanced?

Thanks
Bruce

[Randy Holmes-Farley]

Do we know yet which species might take up more magnesium and which ones take less?

For many, yes. I discuss some here:

Magnesium in Reef Aquaria
http://www.advancedaquarist.com/issues/oct2003/chem.htm

Note that coralline is at the high end.

I was wondering what effect this interruption might play in a low nutrient system such as a ZeoVit system where Ammonia is essentially being "locked up"? Would these systems tend to be more on the low alkalinity side naturally causing long-term issues by becoming unbalanced?

If by locked up, you mean used up rapidly by bacteria with no net production of nitrate, then there should be little effect on alkalinity. The bacteria give back any depleted alkalinity that was lost in producing the nitrate in the first place, and it it stops at ammonia, that balances out too.

[wramy]

Just what I needed to know, thanks Randy.

[Randy Holmes-Farley]

You're welcome.

Happy reefing.