hi everyone this is my first grow . this is my equipment im using yield grow 48x72x96 tent ipower 1000 watt ballast with air cool hood running it on 600 watt on 18/6 with a 6500 mh bulb . the girls are in five gallon pots they have been in the soil for about 17 days now .. the leaves on the bottom are like changing to a light yellow brown color from the tips to the inside any help will be greatly appreciated