Need help tips drying out and die

This is not the first time this is happen. The tips of the plants seem to be drying out and dieing. This is all taken place in a growbox. I am growing with cfls, there is about 5 45w. The temp is around 95 f. I feed the plant once every 3days with bottled water, alternating between nuts,fox farm grow big, and just water. The top of the plant is about a inch away from the lights. I do not know what is causing the prb any help would be apprecatied.

your heat is too high and oyur lights are too close. get a fan in there to mix the air. Give her some mroe soil and put her in a black pot, white will stop root growth.