pH inbalance?

Good Afternoon!

3x3

sf2000 (~20 in away at about 35-40% gives me about 280-300 PAR)

ffhf

Plain RO water ( 0004 ppm and 6.5-6.8pH)

planted 5-15-2021

Cookie Kush is the top plant, the leafs dont look to heathly. I checked run-off ( 2064 ppm, 5.45pH). I did water more with 6.8pH to “flush”. I then checked and the readings are 1278ppm 5.58pH.

Does this look like a pH inbalance? I have not given anything but RO water since sprouting. I water to 10% runoff every 3-4 days. Trying to achieve a good VPD of 0.9kPa. My avg temp and Rh is 77F and 76%Rh. I am trying to lower the Rh.

The other 2 are purple punch and blue berry OG. They are in range of ppm and pH.

Thank you for your help!