How do I mitigate nitrogen toxicity quicky.

Your water ph is definitely too low, you’ll want to balance it to 5.8min-6.7maxium. Another solution might be to use microbial inoculante. If you start to use microbes like great white, recharge, etc. It will help with nutrient cycling and abiotic stress. When using microbial inoculants and testing the ph of the soil, the microbes actually make the ph of the substrate fluctuate which allows the plant to absorb the proper nutrients it needs during these ph fluctuations. Besides that the microbes help convert organic matter into food for the plant and the microbes can also help prevent over/under feeding. Edit: just saw your issue with ph being too high, this is fine watering with low ph for now but you’ll want to keep a close eye on your runoff ph!