University of FloridaSolutions for Your Life

Download PDF
Publication #Cir102

A Beginner's Guide to Water Management -- Nutrients1



Nutrients are substances required by all organisms for growth, and they are found in every aquatic system. Nutrients are also the object of much discussion by lake management professionals and the general public who are concerned about the influence nutrients sometimes have on the growth of algae and/or aquatic plants in lakes. Written for the lay public, this information circular is an ideal reference booklet for students and/or professionals interested in water management. Thirty-two pages in length, with plenty of supporting graphs and photos, Circular 102 is divided into four segments:

  • a basic introduction to algae, phosphorus and nitrogen;

  • discussion of the concept of limiting nutrients;

  • conceptual and mathematical tools that can be used to achieve water management goals;

  • appendix.

Note: Circular 102 is available in Portable Document Format (pdf) only. It can be obtained as a single PDF file by clicking on the "Printer Friendly Version" link above (file size = 1.5MB).


Algae, methods used to measure algae, the role of algae in waterbodies, When Are There Too Many Algae?, Algae and Fish Kills, Health Concerns, biological productivity, chlorophyll, empirical models, limiting nutrients, logarithmic scales, phosphorus, total phosphorus, nitrogen, total nitrogen, trophic state, TN/TP ratios, suspended solids, dissolved solids, hydraulic flushing, and aquatic macrophytes.



This document, CIR 102, is the second of a series of information circulars dedicated to familiarizing citizens with the language and techniques used by those involved in water management within the state of Florida. First printed in January 2000. This is the second edition, published in August 2000. Reviewed by Mark Hoyer July 2013. Printed copies are available through the UF/IFAS Cooperative Extension Service and/or from the LAKEWATCH program itself. However, they may also be downloaded by visting the EDIS website at or the Florida LAKEWATCH website at


Florida LAKEWATCH is a research program coordinated within the UF/IFAS Department of Fisheries and Aquatic Sciences. LAKEWATCH facilitates public involvement in the management of Florida waters by training citizen volunteers across the state to collect monthly water samples, algae samples, and water clarity information from a lake or waterbody of their choice. Over time, these data are used to document nutrient levels and to predict biological productivity. For more information about the monitoring program or to obtain LAKEWATCH data, call 1-800-LAKEWATCH (1-800-525-3928) or search the website at

Photos used with permission as credited.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.