Water Testing for Aquaculture Systems By Edward C. Meisel III September 13 th, 2001

Upon completion of this lesson, the student will be able to: To determine the different ways of testing water quality To learn how and why to test for pH, dissolved oxygen, carbon dioxide, ammonia, nitrite, and hardness To get a basic understanding of how water quality effects fish

Importance of Water Testing Aquaculture Systems A high quality water is the most important thing in a aquaculture system. Water Provides: –Food –Oxygen –An excretory site –Maintenance of body temperature –Possible holding of of disease causing organisms

Water pH pH tests are the most common water test pH is a measure of the hydrogen ions in water pH scale is from 0 to 14, with 7 being neutral pH levels above 7 is basic and below 7 is acidic Most fish will die or mutate when pH levels go below 4 and above 11 on the scale

Dissolved Gases in Water Oxygen O2 Carbon Dioxide CO2 Nitrogen N2 Ammonia NH4+ NH3 Hydrogen sulfide H2S Chlorine Cl2 Methane CH4 *Must all be tested on site

Dissolved Oxygen in Water All aquatic animals require dissolved oxygen for life Aquatic species need at least 4 to 5 ppm to avoid stress Temperature, light algae, and population affect dissolved oxygen levels

Carbon Dioxide in Water Carbon dioxide is highly soluble in water Carbon dioxide buildup from respiration can harm the animals when the level is too high Most carbon dioxide occurs from respiration Aerating water is the best way to keep oxygen levels up and lowering carbon dioxide

Ammonia in Water Tested with special ammonia test kits Algae use ammonia as a nitrogen source for making proteins The majority of ammonia in water is in the non-toxic ionized form. Can be harmful if levels get too high but most of the time is non-toxic to fish.

Hardness of Water Hardness of water is determined by the levels of calcium and magnesium. Low or high levels of calcium and magnesium will effect production.

Testing Methods of Water There are several tests for water, although two are the most common. –Colormetric Uses a concentration reaction Shows test colors Can be read on a scale –Electronic Most aquaculturists use this form of testing Electronic device Gives accurate reading for almost all aspects of water

Resources Agriscience and Natural Resources Education Curriculum (3000) Core Area –Animal Science (3070) Unit Title: –Aquaculture (3073) Topic –Water Testing for Aquaculture Systems u.edu/agriscience/300 0/3070/3073/3073wat ertesting.htm