Question about planted aquarium and fishless cycling

This morning, approximately 9 hours after bringing the ammonia level up to 2ppm, I checked my levels and findings were: ammonia 1, nitrite 0.25, & nitrate 80. This evening, approximately 20 hours after ammonia added, findings were ammonia 0.25, nitrite 0.50, and nitrate 80. The pH has remained at 8.2.
I added more ammonia to bring tank to 2ppm again. Increased temp to 80 degrees F. I will see what it does tomorrow and then decide if I want to do a partial water exchange.