Liming the water inlet sav^^s scattering the lime and is therefore cheaper than 

 scattering on the ground or in the water. The liming of the water inlet is almost 

 indispensable, with acid influxes to winter ponds, trout ponds, etc. A very primitive 

 poorly acting method is simply to throw lime into the inflow ditch. Far more effective 

 on the other hand is the liiaing of a large pond, from which the improved water is then 

 taken for the winter ponds. The sin^jlest and cheapest in the long run is liming by 

 machine, with the lime mill (see Fig. 52). This kind of lime distributor can be con- 

 structed easily in a blacksmith shop, from old bicycle chains, cogwheels, etc. They 

 are now produced clean cut and suitable on the factory scale. The essential part of 

 the lime mill is a funnel (Fig. 52), which has an adjustable slot below-. Finely ground 

 lime is filled in at the top. The lime is continually forwarded downward by a stirring 

 device inside the funnel and a tapper device on the outer wall of the funnel both operated 

 by a chain drive from the water wheel. The purchasable machine is furnished with a top 

 or bottom placed wheel. The wheel is set in motion even by a water inflow of 1 liter per 

 second. In one week 110 to 2,200 pounds of lime may be used up, according to the size 

 of the slot and the inflow velocity of the water. The greater the water flow, the more 

 plentiful the automatic liming. An acid combining value (A.C.V.) of 0.5 can easily be 

 increased to a double or threefold value by lime marl as well as by burned lime. 



This lime mill has worked very prosperously in exceedingly large numbers of winter 

 ponds having acid inflows. Only vdth its help has it been possible to rescue wintering 

 fish stock from perishing on account of too low pH values. The value of liming can 

 hardly be correctly expressed in figures. In very many ponds, in fact, commercial 

 operation is only possible after liming. 



Fig. 52. Lime distributor for the mechanical liming of water inlets. 

 An under-driven T;ater wheel in the backgroimd. In the front, a lime 

 hopper with an adjustable slot in the bottom, stirring arrangement 

 within, and hammering arrangement on the left side. The factory- 

 made liming machines are covered on all sides by sheet metal walls. 



In many other cases the conditions are so peculiar that generalizations cannot be 

 deduced from them. Ilolte calculated on the basis of purely fertilizing experiments in 

 five very different Prussian carp fisheries, in v;hich 330 to 3,520 pounds of calcium 

 oxide per hectare (133 to 1,425 pounds per acre) were given, that 1 dz (220 pounds) of 

 calcium oxide caused a growth increase of 1,68 kilograms (3.7 pounds) of fish flesh. 



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