@Salamisaft
The plant looks like it is already in flower.
In flower, you use a pH from 6,0 - 6,5.
In the vegetative time, you use a pH from 5,5 - 6,0.

Is this an auto or a regular seed?

I have a grow report with one week of vegetative time.
Take a look at #grow0013
https://mastodon.social/@SisterLover/114794350228373093
This is week two, which should be in your time range for your plant.
https://mastodon.social/@SisterLover/114409128156812872

also #grow0014
This is week two, which should be in your time range for your plant.
https://mastodon.social/@SisterLover/114409134053475590