E8 PHOSPHORUS CONCENTRATION SRP (soluble reactive P)[micro g l-1] Year SRP 1967 25-55. 1968 10-20. 1970 14-25. 1979 9 Source: Allanson, B. R. (1979) The physico-chemical limnology of Lake Sibaya. Lake Sibaya (ed. Allanson, B. R.), pp.42-74.