The stock culture was maintained in Berlin tap water with a
mean Ca2+ concentration of 2.5 mM. This relatively hard water
was chosen to avoid any risk of potential acidification by adding
the leachates, which might be acidic. In order to evaluate only
the impact of the biogeochemicals on the life performance of the
cladocerans, the development of further stresses, such as crowding,
with the subsequent development of males, was avoided. The densities
of individuals, therefore, were evaluated in pre-tests which
allow pure parthenogenetic reproductions. All exposure scenarios
with the leachates were not stressful with respect to crowding, because
males did not occur. Only 3rd generation neonates were used
for the experiments. In each 500 mL Erlenmeyer vessel, 30 individuals
were placed; the vessels were kept in a water bath at 30 ± 1 C
and illuminated by cool white light in a 14:10 h rhythm. Lifespan
and reproduction assays were carried out in duplicates in two
independent trials