Light emitting diode (LED) light as an alternative to fluorescent for whole effluent toxicity (WET) organism reference toxicity testing and culturing

In the global transition from fluorescent to light emitting diode (LED) lights, there has been limited research to determine the impact of different light types on whole effluent toxicity (WET) test organisms. This study compared WET testing results, using sodium chloride as the reference toxicant, for Ceriodaphnia dubia, Daphnia magna, Daphnia pulex, and Pimephales promelas kept under fluorescent and LED lights. Inter-laboratory comparisons were made for acute and chronic C. dubia, acute D. pulex, and acute D. magna test results, where seasonality impacts were determined for all tests. One laboratory further evaluated culturing board effects over 12-week periods for C. dubia and D. magna and compared different LED light temperatures for C. dubia. Time of year differences were found with inconsistencies observed between laboratories. LED light temperature did not affect C. dubia culturing or WET test performance. In conclusion, LED lights are a viable alternative to fluorescent in WET testing except for chronic P. promelas and potentially chronic D. magna testing.