To avoid separation of sediment ingredients and re-suspension of fine material during addition of test water in the water column, the sediment can be covered with a plastic disc while water is poured onto it, and the disc is removed immediately afterwards.
For at undgå separering af sedimentets bestanddele og resuspension af fint materiale under tilsætningen af testvand i vandsøjlen, kan sedimentet overdækkes med en plastplade, mens vandet hældes i. Plastpladen fjernes derefter straks.