Help with Phosphorus deficiency

Hi All:
Thanks for popping in , Just looked at one of my plants And it is showing the early signs of a phosphorus deficiency
(purple splotches on the leaves).
Ill give you a run down then I will go get a pic as well.

My plant :strain: great white shark , grown in Pro-mix/perlite/dolmite lime , day 28 of 12/12 , and its in a 6.07 gallon pot
Nutes : general hydroponics flora trio grow micro bloom. last fed the plant 3 days ago 1/2 strngth after it just had water the previous feeding.
I ph my nutes to 6.5 before they go in and the runoff is slightly more acidic 6.3 ish on average.
I grow under CFL lighting

Mainly what I was wondering is " can I add a few liters of water/bloom solution to boost my P now or would this possibly lockout other nutes,
or is it better to wait and just give it a good feeding ( 3-4 days away)
I am going to take pics now and will be up in about 5 or so minutes... sorry seven-10 i forgot i rolled a joint
Thanks for reading +rep for replies and opinions that will help

Here is the pics . The closeup is the worst of it and its not everywhere yet so I am not panicking.
It is a crucial time in its development and just wanting to learn what experienced growers best practices are
in this type of situation.. THanks again!

Day 28 i would definately be lookin to do a Phos boost also. Great idea. Definately wait until your soil is a little more dry so that you can give it a good feeding. The plant will not be able to absorb it as well if you dont let the soil dry up first.

Looking good, what recipe are you following? I do LUCAS, 8ml/Gal micro - 16 bloom uring last week of flowering plus Kool Bloom and 3G:5M:10B at the beginning. This nutes are low on Mg/Ca so Calmag is a must have.

Cant answer definitively, but I can say that I once fed my potted plants a high P feed. This caused an N (and other nutrient) lockout that quickly manifested itself with yellowing lower leaves and stunted bud growth. Luckily, that same week I happened to read Uncle Ben's Gardening Tweeks and Pointers https://www.rollitup.org/advanced-m...989-uncle-bens-gardening-tweeks-pointers.html--- I asked him about what I had done and he answered me back that I had caused an N lockout with the high P food. I was able to quickly reverse it with a properly balanced food-- bringing back the green leaves, heavy bud growth and dank smell my garden had before the high P food.

Kool thanks all for the quick responses + rep comin your way!
I have decided to hold off and just make sure it gets a good balance in 3 days
unless it looks a lot worse. I have room to up my dose of food I think I've been pretty light on them so far.
THanks again . anyone else has a say I'm always interested in learning!