Add your Ph down 1ml at a time ,
always take your ph after you have added any nutes etc to the water,
If your ph is high , you should never add ph up,
If your ph is low , you should never add ph down,
i have good experience with customers asking the same everyday,
follow this you will be fine,
Clonex..
Ps , clean your syringes with ph buffer 7 or filtered rain water...