Power outages can happen anywhere and anytime for various reasons. This threat affects also scientific work of biologists. Especially problematic area is aquatic animal husbandry, where life support of the animals is dependent on continuous electricity supply and years of scientific work may depend on the well-being of these animal stocks. Therefore, tools to estimate and control these risks are needed. In this study, I have used modeling to estimate aquarium water temperature changes during power outages and constructed simplified models for zebrafish aquaria. A calculation worksheet is also provided to help to model kinetics of water temperature changes in zebrafish facilities.