Yellowing and lightening of leaves

Hey there man don’t worry to much there is always a plant in tent that wants to act up I’d suggest checking the ph level of the run off water next time you water and if it’s off run a few gallons of water ph to 6.4 Also every plant requires different amounts of nutrients some want a lot some want a little. It’s possible what your seeing is the plants turning yellow might need a little extra nutrients compared to the nice and green ones If you are using a flowering base nutrients that should be good maybe just add a little extra bites to those plants fee water if the ph is not off Also if you have not started giving cal mag yet do that. It’s possible you have a slight cal or mag or nitrogen deficiency Again like i said don’t worry at all your plants look great it’s very minimal problem going on from what insee