I am on day 11 of a fishless cycle on my 125 gallon tank. At the beginning of the cycle I added tetra safe start. I started with 4 ppm ammonia which dropped to 0 in the first few days. I added 4 ppm ammonia again on day 7. Currently ammonia is 0, and nitrite is around 5 ppm. Nitrate is oddly at about 20 ppm. How is nitrate so high without any decrease in nitrite? Also, my pH is 8.4 though my tap water pH is 7.4, why would that be?