Control of Hydrodictyon reticulaturn Lagerh. and Pithophora oedogoma Wittr. in warmwater hatchery ponds using copper sulfate, sodium arsenite and abietylamine acetate is discussed. Some of the disadvantages of these chemicals as algicides for hatchery use are presented. A method of controlling the above species of vegetation in hatchery ponds using abietylamine acetate is described and recommended for use where either copper sulfate or sodium arsenite has not given satisfactory results.