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.
The Starbucks coffee with 'three quarters of the safe daily dose' in one cup. 1  400mg of caffeine is the recommended daily allowance for average person. 2  16oz Starbucks 'Grande' contains 330mg, according to study. 3  But scientists stress that tolerance levels of the stimulant can vary widely.