I usually get home from the gym at around 9pm and drink a whey protein shake that has 60 grams of protein. I wanted to start takin some casein before bed. Should I add it to my shake post workout or should I drink it at midnight before bed. Also what ratio of whey to casein should I take if I use it post workout and how much casein should I take if it is right before bed. Im 6', 185 lbs with about 14 percent bodyfat.

Save the casein for before bed or during other times during the day. Casein is a very slow digesting protein and you do not want that post workout. The amount you should be ingesting depends on your daily caloric needs. Figure out how many cals you need per meal and then you will find out how much casein you need. Adding flax or peanut butter to your bed time shake are good choices to bring cals up.

as pursuit said, use strictly whey (dextrose if u wish) PW. cassein is best i find right before bed or upon waking up in morning. When i run out of cassein i eat some cottage cheese before bed. Use something like www.fitday.com to find out your daily nutritional goals