hey there, when using dry nutrients to amend your soil always make sure the plant can handle it. Usually for dry nutes the nutrient company assumes the plant is beyond seedling stage. That's because at the seedling stage the plant can't handle much through it's under developped root system. That's actually why you got nutrient burn . Careful watering until run off, run off means you're loosing nutrients, and if you're a pre amended (like me), you actually dont want any run off. So the problem has stopped spreading, next time do a transplant and you'll avoid this situation as well as accelerate the growth. Hope this helps ! 🚀