Help! super Low Ph

Hi everyone!

today is first day of week 5 flower and gave them just phd water at6.8 but both my plants runoff Ph is in the low 4s!

i don’t see anything on the plants but I know I’m going to with my ph being so acidic.

what do it do to get that up? Should I flush with PhD water to get that up?

don’t want them to Go bad on me so close to the finish line!

i also don’t get why ppm would be in 2000 range. Haven’t fed them in two weeks and that won’t go down. I transplanted to FFOF soil on June 7th.

Please Help!