Q-Tank Cycling Question

[trilinearmipmap]

Beverly,

You stated that the tank seemed to be cycled, then you got an ammonia/nitrite spike after cleaning the tank and introducing the fish.

Perhaps instead of having cycled filter sponges in the tank, the large growth of cyanobacteria was consuming the ammonia, so when you tested the tank prior to introducing the fish, ammonia tested zero. After cleaning the tank (removing the cyano) there was nothing left to consume the ammonia.

Just my opinion.