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.
Cup of coffee. If you thought Red Bull was bad, you might be surprised about how much caffeine is really in your favourite drinks. The amount of caffeine the healthy adult should consume a day is up to 400mg and the normal amount in 12-ounce coffee cups contains 90 to 120mg. But one 12-ounce 'tall' or small cup of Starbucks actually has as much as 260mg of caffeine per cup, Business Insider reports.