Two questions

Dear EFDC team and users: I have 2 questions: 1.What does that means:diatoms (mg/L as c)? Diatom alge caculated by carbon? How to caculate? And why doesn’t the simulation change ? 2.What the real meaning of COD in EFDC? I heard that COD in EFDC is not the same meaning with that in china.And the simulation also doesn’t change…
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  1. It is diatom algae concentration as Carbon. That quantity is measured by laboratory analysis using the ash-free dry weight method. It is not the same thing as the concentration of chl-a that you might get from a photometer, as that method can pick up the signal of pigments other than chl-a. I have attached a document regarding this which was published by the United States Geological Survey. Hopefully, this will be a helpful resource for you.2. You can find more information about the Chemical Oxygen Demand (COD) on our knowledge base here: https://eemodelingsystem.atlassian.net/wiki/spaces/ETG/pages/2356262/7.2.3.6+Chemical+Oxygen+DemandHope that helps.

Thank you very much.I think this information will help me a lot.I’ll read it carefully