Responses of individuals, populations, and communities to future climate change can be elucidated via experimental manipulation. However, researchers’ ability to realistically simulate future temperature regimes has been constrained by existing technology, which currently allows manipulation of daily maximum and minimum temperatures but does not allow for fine-scale thermal changes that mirror diel temperature increases and decreases in aquatic environments. We are presenting both the design and performance of a low-cost temperature control system that was developed to address this problem. The configurable system is able to dynamically control the temperature of aquarium or mesocosm tanks .
This temperature control system uses common hardware interfaced with Raspberry Pi microcomputers that can be configured via software to perform in different experimental contexts. The hardware and software support configurable temperature probe and heater assignments, with the ability to leverage multiple dynamically controlled heaters per tank, as well as multiple temperature probes per tank. The system utilizes off-the-shelf aquarium heaters to flexibly scale to various experimental contexts. The system has been successfully used in several experiments. One of the experimental contexts this system was designed for was for installation in temperature controlled rooms. In this configuration the system supported ongoing dynamic temperature control of 2.5-gallon aquarium tanks. The system has supported complex multifactorial experimental designs of up to 14 temperature combinations that have run for 10+ weeks. The same system components were also installed to support outdoor mesocosm experiments. In this context temperature set-points can be derived from configurable ambient tank offsets. An ambient treatment can be configured with other treatments maintaining a dynamic temperature offset. The mesocosm configuration supported an experiment utilizing 48 190-L tanks.
Creating realistic temperature profiles is necessary for a clear understanding of the potential effects of future climate change in aquatic systems. However, most scientists do not have access to equipment which allows for customizable, flexible temperature scenarios that change on appropriate timescales. Our system is relatively inexpensive and serves as either a customizable blueprint for a similar system, or a framework from which others can expand to test other aspects of future climate change in aquatic systems.