Ammount of ammonia when cycling

[tombin]

I'm sorry if this has been answered, but I was unable to find it in the cycle faq or in other posts. Why is 4ppm of ammonia the magic number to cycle a new tank? I've seen people with posts here where they said 8ppm failed. Could someone help me understand why?

 

[adadkins1]

Normally 4ppm is all you need. If you do 8, it will just prolong your cycle and it will create a surplus of beneficial bacterial colonies. 4ppm is enough to create a sufficient amount of colonies to handle a tank that is fully stocked after the cycle. Basically 4ppm is the "magic number" because it creates just the right number of bacteria.

 

[eco23]

Normally 4ppm is all you need. If you do 8, it will just prolong your cycle and it will create a surplus of beneficial bacterial colonies. 4ppm is enough to create a sufficient amount of colonies to handle a tank that is fully stocked after the cycle. Basically 4ppm is the "magic number" because it creates just the right number of bacteria.

Great answer. The truth is that 4ppm in itself is designed to be overkill to ensure your tank is as stable as possible before adding fish. It creates a tremendously strong bio-filter. If you have a tank that requires cycling at higher than 4ppm...it is WAYYYYY overstocked. Higher amounts of ammonia can also lead to excessive no2 during a cycle potentially resulting in stalls.