hey i jus started flowering on the 18th and ive had some signs which appear to be chemical burn. im using a foxfarm combo....one is bubba kush and the other is white diesel (rhino X diesel, i guess) both from clones ....im thinking bout doin a flush today, but i need sum advise first, this is my first time grow. also gettin a PH and ppm tester today. the tips are getting dark on both, but the white diesel is droopy and two leaves turned yellow at the bottom so i clipped them off. the bubba is also dark at the tips like brown brownish color....i had jus topped both of them like 2 weeks b4 beginning flowering....the pics tell more then i can say with my knowledge so please please help! thanx! 
the light is a mh, not sure what brand or color spectrum, but its 400w....i used the foxfarn grow big 6-4-6 for veg....so should i be flushing it?? oh and i did one foliar feeding that i dont think i shoulda done using tha solution 
...is it possible i wont needa flush, jus straight water for a while and clean leaves???
