PH drop problems

Hi growers. I have been flowering for about 17 days now and i had a little ph problems b4

they were creeping too fast so i have to ph down it everyday

some info:

nutes bionicare pure blend pro grow and bloom, cal mag plus, liquid karma, and sweet
lights about 1 foot from tops
temps are about 77 the room and 72 in the resivoir
i have killed 6 males and left with 4 females.
light 600 watt hps
also can i add the other 600 hps or would that be over kill cause plants arent in taking too much space

they are bubbleponics in 5 gal home depot buckets with a18 gal resivior feeding the 4 5 gal hd bucket and draining in to the resivior while a tube plumbs water into the 5 gal
and drains to the res again

well my problem is that ph didnt go up this time

ph droped from 5.7 -5.1 in 6 hours or so i believe

i have noticed symtoms of ph lock out cause the leaves arent flat they kinda bend down and looks shiney

some leaves look wrinkles and bad..

anyone know what the ph is going down..

ohh yeah i added extra airstones in each bucket thinking more air is better and i raised my nutes ppm from 900 to 1200.

im gonna lower nutes back to 900 and see if that does anything.

please give me your opinions..

thank you