Dear Dr. Mueller:

Thank you for submitting this paper to Biogeosciences. Two referees have evaluated your manuscript and gave constructive feedback. Based on the reading of your manuscript and your rebuttal, I believe that a revised version will likely be acceptable for publication in Biogeosciences. I therefore invite you to submit a revised version of your paper. While revising your paper along the lines of the reviews/rebuttal, please try to rewrite so that the research questions are more articulated. You present high-quality data and by providing more (historical) context, e.g. why not cite Ditoro et al. (1990) sediment oxygen demand model for lakes and streams paper (J.Environ.Eng, 116) or Soetaert et al. (1996, GCA) who introduced the oxygen demand unit concept in marine diagenetic models, your paper would strengthen further.

With best regards, Jack Middelburg, Associate Editor

Dear Dr. Muller, dear Beat:

I have read your rebuttal and revised version and I am happy to inform you that your paper is now accepted for publication. While reading I identified a few minor issues that might need correction.
- Hyphen bottom-water if used as adjective
- P. 11, last sentence of section 2.1. It is not 100% clear whether this refers to all lakes or just Lake Zug (as I understand).
- P. 13: Lake Aegeri (Figure 1a, b). Nitrate …
- P. 14, middle of page: At 79 m, a markedly..
- P. 17, first line of section 3.4: .. fraction of aerobically mineralized OC…. (one usually uses aerobic/anaerobic for the processes and oxic/anoxic for environmental conditions).
- P. 18, line 4-5: a closing ) is missing.
Thank you for submitting this thorough work to Biogeosciences.

With best regards, Jack Middelburg, Associate Editor