Canna nutrients Estimated 3/4 weeks remaining gelato late stage deficiencies?

[Iwishiknew]

Hi people
First grow posted a few times during the past few weeks thanks for everyone’s help
I’m starting to see lots of brown spots and yellowing at this stage suggesting it’s either zapping nutrients or it’s not up taking certain ones?
I’m pretty much refilling with a fresh batch of nutrients every other day following the canna terra grow program.
10ltr dwc 4” air stone
Really pleased with the progress but not really sure what I’m looking for ?
I’ve read that it can be normal towards the late stages in certain strains this being gelato from uk seed bank
Could anyone share their knowledge/thoughts
Ph remains stable between 5.9 and 6.1
I’m at roughly halfway through flower I think ,nutrients at the highest I’m in the final few days of pk 13/14 before easing off. ec of 2.4 dropping to 1.9 at refill time
Any help appreciated

 

[AZreefer]

this help you?

 

[AZreefer]

You sound like you're running a tight ship and you are making awesome progress. What's your temp in your tent?

 

[Iwishiknew]

Thanks to low apparently went to my local grow shop first word out of his mouth temp too low.
Until yesterday I was running a low of 17 and high of 22, up to a low of 20 now and high 25
And added some de stress stuff can’t remember its name ice something I think I will let you know how it goes
Again much appreciated