Autoflower day 52, yellow leaves, would appreciate some opinions, thanks

[nickmetal]

Hello Ladies and Gentlemen.
I cultivate 2 Autoflower plants,day 52 currently and i have some yellow leaves down under.
150W led lamp,soil light mix,biobizz nutrients a bit lower dose than their plan.
Had some discoloration that looked liked Mg shortage,gave it one dose 3 days ago yet still got yellow dyiing leaves
down there but not the same discolor pattern.
I water with 7ph bottled water,never checked PH further.Not wise i know.
Maybe it is normal for lower parts to die due to suck up the nutrients?
Is it ok at this time of flowering?Despite this they look ok ,i water untill i see some excess every 3 days.
Should i flush/buy ph pen at this time of grow would help?Maybe ph is bad and cannot use all nutrients?

It is my first indoor grow and i am not really sure how to proceed,have a nice day and thanks a lot.

 

[SparkNShred]

They look pretty damn good to me. Two or three leaves yellowing is no big deal. Someone with more expertise may say different, if so definitely pay attention to them not me, lol. Congrats on a beautiful first indoor auto grow!

 

[nickmetal]

Thanks for your reply sir,i cant stop looking/thinking at them
Well situation looks like stable at the moment,i didn't see new fan leaves with mag def signs since i gave one dose of calmag 3 days ago.If i see new problem i shall add a new dose.
Tonight i shall feed girls again,i shall use ph meter to adjust water+nutrients from this point on.
Still i am not sure if i have to flush soil ,i do not know if it benefits at this stage and if i will stress my girls
with no real benefit.

 

[cbdhemp808]

Hi @nickmetal and welcome to the forum! Nice looking plants! I wouldn't worry too much about those lower leaves. If it was me, I would just pluck them off. One question... what does the underside of one of those leaves look like that are showing yellow spots on the top side? Do you see dark spots underneath?