Archer, C. 2021. Zebrafish water quality for laboratory animal technicians. Laboratory Animal Science Professional 9(4) (July/August), 11-13.

Zebrafish are an increasingly popular model organism in many aspects of animal research; however, some aspects of their husbandry needs are quite disparate from that which most lab animal technicians are trained. Possibly the most important aspect of zebrafish husbandry is water quality, which has impacts on all areas of the life of a laboratory zebrafish. Water quality is a very complicated chemical concept, with the different parameters often intertwined in ways that seem daunting for many technicians. However, with a solid grasp of the different parameters of fresh water and how they interact with each other and have implications for fish health, lab animal technicians can establish a solid background to manage a recirculating water system housing zebrafish. This article describes pH, conductivity, alkalinity, hardness, dissolved gas, and nitrogenous waste. While zebrafish users and caretakers should aspire to a more standardized set of desired water parameters for laboratory zebrafish across most facilities, the most important thing to consider about water parameters is that they should remain as stable as possible, as long as they are within a safe range for zebrafish health and welfare. In many cases, unstable water parameters can have more detrimental effects than levels that are slightly approaching the range of what is considered “acceptable” for housing zebrafish. Work to keep the system stable, and then work to see if it is possible to gradually change system parameters to the values you desire while still maintaining stability.