Hey BK, I got the same problem. I got purple kush in a 3 gallon also with Fox Farm Ocean Floor and it is 4 inches from top. It looks like i only put 2 out of 3 gallon of soil in it. It has been in there for almost 9 weeks now. I was thinking about taking the plant out and putting the new soil (FFOF) on the buttom but am worried about shocking the plants. What woulda veteran like you do?