Is it a deficiency or excess ?

Since the last time I watered with only 2 litres of water and 250 ml with a pH of 6.3 for each 12L pot 4 days ago. In the next watering I plan to do it with just water again to continue to detoxify the plants of possible minerals that can clog the roots ... the calmag I do not know if it is a good idea to give them in that watering I do not know what you think ? I don't want to continue to load the soil with more minerals ... but on the contrary to reduce them to unblock the absorption of nutrients in the roots ... so I don't know if I should give them calmag ... ??

Phosphorous deficiency.

Found my comparison for you. Also got some odd brown spots also. 1st pic into 3rd week of flower. growdiaries.com/diaries/141736-grow-journal-by-gottagrowsometime/week/793749

Mag def isn't so uniformed. And can be very deceiving. I see the fade going right through some leafs with greener vains. Also there's no signs of mag on the edges. Look up calmag defs and then iron defs and you'll see what I mean. Good luck

Okay. I need clearer pics. But I can see P def blotches. Then light iron def. (Iron can be mistaken for calmag def) the difference with iron. The fade shows on 90% of the leaf.. its very early. As for the brown spots. Maybe by product of your nutrient lock. So, to get rid off FE def (iron) you need to let your soil dry out. After you give a hard flush as she's locked out. Then when she's drying up. She might just find what she needs in a lighter soil (less hot). But it it doesn't. Most bloom nutrients will have a 0.01 FE. you only need a tiny bit. You are in very early stages. But as I see 3 dif things going on here. Id put it down to lockout 1stly. And these are just coming up lightly now. As if it was just 1 thing, it would show up stronger but as there is a few things going on at the same time. Give her a hard flush. 3-1 of your pot value. So, if your pot is 10L. You put in 30L of water. Try half that. And grab last few 100ml of all. And ppm test it. And if its still high. Continue. When fin. You'll find it you turn the pot on an angle and excess water will drain faster then if you were to leave it sitting flat. Are you using 0 ec water? Good luck pal.

could be nitrogen too much, but its more pH, i see magnesium striping going in too, stupid lightning, can only guess from my own mistakes .... too much nitrogen not only blocks absorption of certain elements, but this could lead to ph swing inside of pot too... just general guesses. bad ph or excess of N blocks calcium, those rusty spots are aftermath. if you grow under leds add calmag 0.25-0.5 ml/L to every second feed and most mistakes will be prevented, but make sure you put right pH and your meter is showing real numbers. i always had double check for ph, aquarium drops cheapest alternative, watch for small range ones, like this : https://media.growdiaries.com/static/post/photo/20573/6219523_grow-journal-by-asnoriuseedsmanalaskan-diesel-auto.jpg