Allan writes, The purpose of the filter course is to prevent fine soil medium particles from washing into the drainage layer causing clogging or reduction of the drainage capacity of the drainage layer.
Just how much caffeine is too much? For the average person, up to 300 mg of coffee a day, or two to four cups of the average brewed coffee, is a moderate amount that isn't harmful. But once you hit more than four cups, you may experience less-than-desirable side effects.
Coffee Cup Consumption Per Day: Men drink as much coffee as women; each consuming an average of 1.6 cups per day. Women seem to be more concerned about the price than men. Among coffee drinkers, the average consumption in the United States is 3.2 cups of coffee per day. Average Cup Size.