Flushin brown spots

My autos slowed growth, leaves curled down n got brown spots n really gettin brown.... I'm about to flush with bushdoctor sledge hammer n here my question....it says2teaspoons per gallon of water but nothin about ph, so do I need to ph the solution with my tester too before watering?

pictures would help on this one- I think I have similar issues on a few older ones myself- not autos but into flower. I think its P or K def for mine, but again some pictures would help. Leaves curling down usually indicative of too much watering or overferting.

hope that helps a bit anyway- later j