Blood Diluted With Hayek’s Solution For The Red Blood Cell Count Whereas Turk’s Solution Was Used For The Leukocyte Count

Why was whole blood diluted with Hayek’s solution for the red blood cell count, whereas Turk’s solution was used for the leukocyte count? And why when performing a white blood cell count, the red blood cells do not appear on the sample loaded onto the hemocytometer and do not interfere with counting procedure?