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.
On average, adults in the United States consume the caffeine equivalent of two to three cups of coffee daily (about 200 to 300 milligrams). And although some believe caffeine may be addictive, it is generally considered safe for most people in reasonable quantities â meaning fewer than five cups a day.