hi to all. this is my second grow the strain is feminized the church. iam encountering problems with stretching. iam 2 weeks into flowering but they seem to be stretching far too much

. plants are around 2 and a half feet tall but the big fan leaves are around 5 inches apart ????? iam using a 600w light on a light mover always keeping them around 8 inches of the top of the plants but wen i leave them for only a 2 day peroid the plants are almost touching the light ???? any suggestions appreciated
thanks