It can be genetic, too much N, too cold, too windy... as long as she goes on growing it’s really not a problem. I have to ask though, have you seen any run off? With that amount of water, you’re probably not getting run off. That means what ever nutrients she’s not completely depleting between watering is building up. If I were you, I’d flush her with a couple gallons of water. Followed by a gallon of 4g/gal MC.
Emilya pretty much summed it up.
Emilya pretty much summed it up.