please help, a few probs

i know im not a newby, so please forgive my question

i am doing a bigger scale grow than normal, i have only done closet grows and greenhouse grows before.

i have 8 white widows, in 12/12 2 every 2 weeks , so all diff stages and plants 4 weeks 12/12, from seeds i got from jamacia, when i went on holiday. under 600 red spec hps


i have 5 blue berry "fem seeds x 5 " all 2 weeks vegg from seed 24/0 vegg under 250 hps

2 topp 44 reg seeds 2 weeks vegg under flos

4 fem lemon skunk
and
4 fem durban poison
under flos, 4 days vegg.

all of above in soil and 1/4perlite.

and 40 rooted clones and 60 still cloning all wwidow



any way i am having a mite problem in my flowering room .
i bought a product "oil to added it to water and spray and it worked at 2 weeks 12/12, but can i use it on 7 week flowering plants, and will it be ok to use while so late on into 6 weeks 12/12.

also any help on hjow to lower my ph what is 8, any thought on what it should be on ww??.

i do flush every week.

can any help
thanks

Plain and simple get some ph up and ph down. 6.5 is ideal ph for soil as for the mites if it says on the oil you can use it up to harvest.....then you are all good

the man said in the shop it was good for 3 weeks 12/12

what is it neem oil or einstien oil???

genius oil.
it was £25 for the bottle, abour $50.