[Coral-List] re: ammonia levels in aquarium waters

Charles Booth booth at easternct.edu
Wed Dec 28 12:53:45 EST 2005

Regarding the potential impact of 20 ppm NH4+ on corals growing in aquaria,
Alina Szmant wrote:

 20 ppm when you divide by 14 (atomic weight of N) = 1.4 uM NH4+

Math has always been one of my weak points, but 20 ppm = 20 mg per kg, (or
ca. 20 mg per L). So, dividing by 14 would give a value of 1.4 millimolar
(mM) NH4+ - not 1.4 micromolar (uM)?  And if the original value of 20 ppm
referred to the concentration of ammonium ion, not ammonium nitrogen (I
don¹t recall it specifying either way), the calculation should be:  20 ppm
divided by 18 (formula or molecular weight of NH4+) = 1.11 mM.
If I have made a mistake here, I apologize in advance.

Chuck Booth
*   *   *   *   *   *   *
Dr. Charles E. Booth
Dept. of Biology
Eastern Connecticut State University
Willimantic, CT  06226

Ph: 860-465-5260
Email: booth at easternct.edu
FAX:  860-465-5213

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