3 months it should be cycled....
but if you used chlorinated water at any time... that could have killed the good bacteria. USually my tanks tanks take 2-4 weeks to cycle. But im diligent with dosing ammonia, etc.
....is what you should be testing all the time.
I had a friend who kept having issues : algea blooms, etc. Turns out, they scrubbed the stones/gravel under the tap water.... they also cleaning the filter regularly (every month) with tap water.... which meant they killed all the good bacteria... and in essence were starting the cycle all over again. Fish kept dying, everything was stressed.
Giving back creates a virtuous cycle that makes everyone more successful (as long as they cycle!)
7 Tanks and counting..... plus all these critters to feed critters