Division 1.8.14 Modification for strongly coloured substances

The irradiation (light intensity) should be in the highest end of the range prescribed in this Testing Method: 120µE m-2 s-1 or higher.

The light path should be shortened by reduction of the volume of the test solutions (in the range of 5-25 ml).

Sufficient agitation (for example by moderate shaking) should be performed in order to obtain a high frequency of exposure of the algae to high irradiation at the surface of the culture.