WATER FOB TROUT CULTURE 87 



Irishes more water than he thinks he can pos- 

 sibly use. Where a spring is of small volume 

 the hatchery supply may be augmented under 

 certain conditions by water from a stream. 

 When this course is pursued it is better that the 

 flow from the stream be used for the ponds en- 

 tirely, and that from the spring first for the 

 hatching and nursery troughs, and then for 

 ponds where the two may be mingled if found 

 most convenient. It is held, indeed, by many 

 fish-culturists, that while spring water is best 

 for hatching trout eggs, stream water is better 

 for rearing fish after they are four months old. 

 Artesian or other very deep wells may be used 

 for the increased supply of water. 



I am one who holds that trout-stream water 

 of good volume, which can be flowed through 

 ponds without causing an undue rise in tem- 

 perature in summer, is better under some cir- 

 cumstances than an outflow directly from a 

 spring. Creek water possesses both aeration 

 and animal life, and is usually a little higher 

 in temperature during the best growing period 

 of the trout, a very desirable feature, especially 

 when the fish are in the fingerling and yearling 



