What source of ammonia did you use to cycle your fish tank?

If you have cycled your fish tank, what source of ammonia did you use for cycling?

The question applies to both fishless cycle and fish-in cycle.


To answer the poll, in the case of you have tried multiple sources of ammonia, please only pick the one favorite source which you have used successfully to complete the cycling. Do not pick the one you like most but you have not tried it yourself, or have not yet completed a full cycle with it.

Aside the poll, please specify the source of ammonia you used.
In the case of pure ammonia was used, please stated the specific product.
In the case of fish-in cycle, please specific the fish species and the number of fish.