198 FISH HATCHERY MANAGEMENT 



Figure 69. Trout eggs being poured into a Montana hatching box. 



These incubators can be set up as either 8- or 16-tray units. Draining 

 and cleaning of each tray is possible without removing it from the incuba- 

 tor. Individual trays can be pulled out for examination without disturbing 

 other trays in the stack. Screen sizes can be varied to accommodate the 

 species of eggs being incubated. Accumulations of air bubbles can cause 

 problems in water circulation, and care should be taken to de-aerate super- 

 saturated water prior to use in this unit. Vertical incubators have several 

 advantages over troughs. They require small amounts of water to operate, 

 and use relatively little floor space. Fungus can be controlled easily with 

 chemicals due to the excellent flow pattern through the eggs. The small 

 quantities of water required for these incubators make it feasible to heat or 

 cool the water as required. 



