The required volume of faecal stock solution for the given treatment was dispensed into 70 ml polycarbonate culture vials containing 25 ml (for the experiment with C. pendulus) or 29ml (for the experiments with P. antarctica and D. tertiolecta) of mod-F/2, that had undergone the same process of metal removal using Chelex resin as
described for the mod-F/2 used in faecal stock preparation.