Question with my Gelato 33 almost 5 weeks into flower

I thought I might start my own post instead of pig tailing another

My plants are 33 days after light change to 12-12. My tallest Gelato 33 is is starting to turn a little yellow. PH has been a constant 6.3-6.6ish. first 2 feedings of Calmag on all plants just started 10 days ago. All plants have been feed the same but tallest plant has been a real grower and perhaps needed more nutes from the start??

I really don't know as I'm a new grower. Just fed Buddha Bloom yesterday. (3rd feeding). I tried to keep it simple and listen to plants without overdoing anything. Could it be this plant is more mature and starting to use its own nutes? No dead leaves anywhere on plant and entire plant is yellowing evenly. It would seem all other Gelatos are still a darker green. Wondering if I should give plant phosphorus?
Any help is appreciated

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Soil is tricky once it starts showing problems it’s usually started a week before but just showing now. Do coco with a simple base nute. I use just the flora micro and bloom now for flowering. But I’m guessing ph problem if your food has enough nitrogen

I forgot to add that my mixtures of Fox Farms ocean and Strawberry fields has prob been running out of nutes . I transplanted to 5 gal pots and extended my nute life in the soil for 30 days but I have exceeded that timeframe. I have also been using Real Grow Recharge regularly since veg. I can add some Nk but was trying to make it to the finnish line without additional Nk. I do have some Buddha Grow rated at 2-0.25-2. I used that per specs up until the second week of flower but not since

Why are you using calmag?
Are you using ro water?

For damage control , I had a few leaves that had very faint rust spots. I thought Calmag would help and no Ive never used use RO water.

larrypizzimp93 said:

Soil is tricky once it starts showing problems it’s usually started a week before but just showing now. Do coco with a simple base nute. I use just the flora micro and bloom now for flowering. But I’m guessing ph problem if your food has enough nitrogen

Click to expand...

Perhaps it is a PH problem. I didn't realize once you calibrate your PH meter you should recheck its accuracy often. I can only reconfirm calibration tomorrow and I can also add that I was pleased when reading the PH of runoff water during a watering a few days ago but that's obviously biased on the current, unknown accuracy of my meter.