Effects of EDTA, FeEDTA and soils on the phosphorus bioavailability for diatom and blue-green algal growth in oligotrophic waters studied by transplant biotests

Biotests with dilute natural populations of blue-green algae and diatoms from the eutrophic Lake Arungen were performed to study the effects of EDTA and FeEDTA in combination with phosphate and soil total reactive phosphate (Tot-Pr) on the growth rate in filtered water samples from the ultraoligotrophic Lake Lutvann. The factor limiting growth other than phosphorus was termed X-limitation.