The leaves are turning yellow. My GDP at 5 weeks since flip. Growing in Happy Frog. Is this nutrient burn? I was fertilizing with Prescription Blend continuously. I changed that couple of weeks ago to pH 6.5 water and fertilizer weekly when first noticed. I have an automatic watering system that I built and programmed. It waters to 50% when moisture drops to 15%. Basically, almost dry to fairly wet. Water about every 2-3 days. Hadn’t had any problems with other grows. Tent temperature is 73-77F. Humidity is at about 40-45%. 1,500 watt led about 14 inches from canopy. Light measured at 500 ppfd.