cycling live rock

Hello all, So, I’ve been cycling live rock in a 30 gallon bin for about 6 weeks now, but I’m confused. When I dose the ammonia to about 3-4ppm, the ammonia is gone in less than 24 hours, but it takes the nitrites 1 1/2- 2 days to be gone. Would anyone know why that’s the case? Will it just take...