Video credit: Carolyn Madalo Chinguo (Malawi)
\nDescription: Abdel Rahman El Gamal (Founder of the video channel)<\/p>\n
This video was filmed in the WorldFish Center-Egypt during a regional training course.<\/p>\n
This 9-min video demonstrates the field testing of total ammonia in water using the color disk kits. The video starts with water sampling emphasizing how to obtain a sample without air bubbles from a designated depth which was 30-cm in this video.<\/p>\n
The demonstrated method can produce fast and reasonably accurate results especially when the individual color perception is high (individual sensitivity), especially this method depends on color comparison.<\/p>\n
The analysis proceeds as follows:<\/p>\n
Place the ammonia color disk on the center pin of the color comparator with the lettering facing out<\/p>\n
Rinse the 2 viewing test tubes using the sample water before testing<\/p>\n
Insert the blank test tube (only sampled water) into the left opening of the color comparator<\/p>\n
Insert the ammonia-nitrogen test tube into the right opening of the color comparator. Add three drops of Nessler Reagent to the water sample and swirl to mix. A yellow color will develop if ammonia-nitrogen is present. Allow samples to sit for a maximum of 10 minutes.<\/p>\n
Hold the color comparator up to sunlight or a lamp and view the openings in front. Rotate the color disk until a color match is reached then read and record the value of ammonium-nitrogen in mg\/l as seen through the scale window.<\/p>\n
The temperature and pH of sampled water should be measured in the same time of ammonia sampling. In order to obtain the toxic (unionized) component of total ammonia (NH3<\/sub>),\u00a0 <\/sub>consult a specialized table that considers the pH and temperature values. As a rule of thumb, the NH3<\/sub> increases (and so the toxicity) as the pH rises.<\/p>\n