My plant has some kind of deficiency! Can you help me out?

Nutrients
22

I only use Bio Bloom with nothing else, around 4-5 ml/L

23

I would try adding cal/mag personally.

24

I finally got my PH meter and this are the results:
I watered the plant with plain water with a ~7.7 PH and the run off was at about 7.35 PH.
I know it is slightly off from the 6-7 optimal PH zone, but does that .35 really metter that much?

25

Range needs to be between 6.3-6.8 above and below that will cause problems
Strips are not accurate enough nor are the drops a decent ph meter is best but a cheap one is better then nothing you can get tem for as little as 10$ @M0bi0us

26

I got one, now how do I lower the ph?

27

I think using ph up and down is best
And suggest you get some
Adjust ph to 6.3-6.8 wheh watering or feeding

28

while I wait for the ph up and down can I use stuff like vinegar to make the water more acidic?