OPERATING THE HATCHERY 



be seen at a depth of more than 12 

 to 15 inches. Fertilizing should 

 then be stopped until the water be- 

 gins to clear, when it should be re- 

 sumed. The objective is to main- 

 tain a constant amount of turbidity 

 in the water. One should not over- 

 fertilize, as the production of too 

 many of certain microscopic or- 

 ganisms will be detrimental to the 

 fish by removing too much oxygen 

 from the water at night and on 

 cloudy days. 



Each application of fertilizer 

 should consist of 100 pounds of fer- 

 tilizer of approximately an 8-8-4 

 formula for each acre of water sur- 

 face. This means that each 100 

 pounds of fertilizer contains 8 

 pounds of water-soluble nitrogen, 

 8 pounds of phosphate, and 4 

 pounds of potash. If fertilizer of 

 this formula cannot be purchased, 

 regular garden or farm fertilizer 

 may be supplemented with nitrate 

 of soda, ammonium nitrate, super- 

 phosphate, or other chemicals. 

 Any fertilizer dealer can give in- 

 formation for modifying regular 

 fertilizers to obtain the proper 

 formula. The 8-8^ formula was 

 first worked out by Swingle and 

 Smith at Alabama Polytechnic In- 

 stitute and is generally applicable. 



There is some variation in fer- 

 tilizer requirements, however, ac- 

 cording to the chemical content of 

 the water. For instance, in very 

 hard water at the I^etown, W. Va., 

 station and surrounding territory, 

 it was found that a 12-5-5 mixture 

 gave best results. In general, hard 

 waters require more nitrogen and 



less phosphorus and soft waters less 

 nitrogen and more phosphorus. 

 Under acid conditions it may be 

 advisable to use lime. At the pres- 

 ent time, there is insufficient knowl- 

 edge to make specific recommenda- 

 tions for all conditions. One can 

 obtain the desired results simply by 

 increasing the amount of fertilizer 

 per application, where a "water 

 bloom" is not obtained within a rea- 

 sonable time. Generally, 6 to 12 

 treatments are required through the 

 summer, depending on the fertility 

 of the water, length of the season, 

 amount of runoff, and other condi- 

 tions. 



STOCKING THE POND 

 WITH ADULT FISH 



A very important step in op- 

 erating the pond is to stock it with 

 the correct number of brood fish. 

 Adult fish seined from streams or 

 lakes in the spring before they have 

 had time to spawn are commonly 

 used as brood stock. Because of the 

 uncertainty of the natural supply, 

 it is desirable for the dealer to hold 

 the brood stock from year to year. 



When selecting fish for brood 

 stock, the dealer should attempt to 

 get an assortment of sizes. For ex- 

 ample, the male fathead and blunt- 

 nofre minnows are larger than the 

 females, while the male golden 

 shiner is smaller than the female. 

 If only the largest specimens are 

 selected, the pond will have an un- 

 balanced sex ratio. In certain of 

 the Lake States, the following rates 

 of stocking of adult fish have been 

 found satisfactory : 



26 



