Diel and Seasonal Variations in Physiochemical Limnology, Speed River, Ontario

Diel pulses occurred in p H, dissolved oxygen, and free carbon dioxide. Iron and fluoride levels were stable. Total alkalinity, silica, and turbidity levels varied, but not significantly. Wide diel ranges existed in ammonia, chloride, nitrate, nitrite, orthophosphate, sulphate, and specific conductance levels. High hexavalent chromium levels (0.57 mg/1) occurred only on one occasion. Diel means of these characteristics showed seasonal change fitting the seasonal trends evident during the year of observation. The nature and extent of diel variation are generally required to determine an effective procedure for examination of local changes in limnologic conditions.