The pressure at which the non-colloidal part of the blood separates from the colloidal part of the blood and enters the capsular space as filtered fluid is called the effective osmotic pressure. The effective osmotic pressure is determined by the capillary blood pressure of the glomerulus, the colloidal osmotic pressure of the blood, and the hydrostatic pressure of the filtrate. The effective osmotic pressure is obtained by subtracting the colloidal osmotic pressure and the hydrostatic pressure of the filtrate from the glomerular blood pressure. If the blood pressure of the glomerulus is 75 mmHg, the colloidal osmotic pressure is 30 mmHg, and the hydrostatic pressure of the filtrate is 20 mmHg, the effective osmotic pressure will be {75-(30+20)} mmHg or 25 mmHg.