Semi-Centennial Volume. 145 



attaching this to the stern of a rowboat near the surface of the water, 

 row slowly back and forth over the reservoir, on each trip keeping the 

 boat within ten to twenty feet of the previous path. In this manner 

 about one hundred pounds of copper sulphate can be distributed in one 

 hour. " 



It is of great importance to determine the exact proportion of copper 

 sulphate to the volume of water to be dosed, since too small a propor- 

 tion will not affect the algae, and too great involves unnecessary expense, 

 and may kill off the fish. The quantity of water to be treated in a 

 large impounding reservoir may be estimated by multiplying the num- 

 ber of acres of water surface by the average depth (taken as about 

 one-third of the maximum depth), and dividing this product by three. 

 This gives approximately the number of million gallons of water in the 

 reservoir. (Whipple 26, page 256.) 



Since some genera of algae require more copper sulphate than others 

 (Moore and Kellerman), it is quite essential that the genus of the algae 

 causing the trouble be determined by microscopical examination. The 

 alg« which appeared in the reservoirs in the two years' survey, and 

 which, therefore, are the most common in Kansas, may be identified by 

 the descriptions in the key and drawings included in this report. 



After the quantity of water to be treated and the causitive organisms 

 have been determined, the dosage of copper sulphate may be found by 

 referring to Table II adapted from Whipple (26) and Kellerman (12), 

 page 9. 



Immediately following the killing off of the algae by copper sulphate, 

 the odor often increases for a few days because of disintegration,' but 

 this soon "passes away. Another effect of the disintegration of the algae 

 is the perceptible increase in the bacterial count. This can be kept 

 down by the proper use of hypochlorite, which has been used to some 

 extent as an algacide, but has been found to be not as satisfactory as 

 copper sulphate. 



When the use of copper sulphate as an eradicator for algae was first 

 advocated, the question arose as to its effect upon the human system. 

 Ample data is presented in the Moore and Kellerman paper to show 

 that copper salts are used medicinally, and that copper is widely dis- 

 tributed in nature, so that we take it into our bodies in vegetables and 

 other food to such an extent that the amount which we would get in 

 copper treated waters would not be at all toxic. 



Aeration also has a marked effect in the decrease of the algae by 

 liberating the carbon dioxide gas, which is essential to these plants for 

 the manufacture of their food. 



10 — Aoad. Sci. — 2199 



