Top canopy getting lighter in color

Ai assistant for plants? Leave it to your feeling rather then a robot. Not all signes are clear. IMO your plants look fine, I cannot see any crazy deficency. Just the Preflower lighter green for now?

ai Assistent that is your major malfunction right there

Newt loop has a solid point, you been Feeding that dose since week 1, far too much calmag given your growing in soil not coco.

It says in your last diary comment that you gave 25 ml of calmag in 10l of water. That's 2.5/ml per liter and is quite a strong dose. Normal dose is 1 ml/l. Calcium toxicity will make phosphorus fallout and will show signs of potassium, magnesium, iron, and manganese deficiencies. It also makes plants more prone to light and heat stress, causing top leaves to turn quicker.

60% daytime RH at 72F is insanely moist for a tent holding that much plants, as the plants grow they create a much larger respiratory footprint, especially at night. We optimize every detail of daytime, we tend to forget about photosynthesis and its nighttime brother "cellular respiration". 60%RH at night is easily going up to 75+%. This will trigger plants to start to close their stomata and cease to process any energy and carbon collected during day. If water vapor cannot escape from the leafs at night because rh is too high, no new water can come up, meaning no nutrient, less cooling. Nutrients build up in medium over time as water is not cycling causing ph to drift, this will appear as nute deficiency but it's not its likely just ph drift. Solution: Check ph, check ec. Control rh to get water cycling correctly again, if ph is outta whack deal with that first.

1300 ppm is fine for plants that size. I don't know much about your nutrients, but I checked a few other grow logs that used them and were in flower or harvest stage. Seems like in veg they were all adding a calmag supplement. That would explain your symptoms, a lack of calcium. Will likely get worse since you ran straight water this feeding/water. Wait till they dry out a bit hit with nutrients and add some form of cal mag supplement as well. Good luck, I hope it helps. Calcium is immobile meaning it will show at the top of the plant Nitrogen and magnesium are mobile meaning they can steal nutrients from old leaves and would show symptoms at the bottom of the plant FYI.