i reckon your lamps are to close and/or the temperature in the room is to high. the best temperatures are between 75 and 85.
could also be nute burn and as 'disrupt86' said it could be insects so what you should do is go over everything again, check for insects, get the temperature lower, check your ph and maybe flush your plant to..to check if the light is to close put your hand at the top of the plant and see if its hot..if it is higher the lamp..if you have already done all of what i said well then im sorry i cant help you...good look geting her better though