Explain fishless cycle stall

[Digger]

I have heard that while doing a fishless cycle and your nitrites fail to come down, your cycle may have stalled and doing a 50% water change can get it going again.

Can someone explain this to me? From what I know about the nitrogen cycle, I just don't understand how the cycle can stall and why removing a big chunk of your nitrites with the water change restarts the cycle. Sounds to me like ammonia was overdosed causing a huge spike in the nitrites. Then the water change brings the levels back down to a level that you can now read and then continues coming down thus giving the illusion that the cycle was stalled and restarted. If you didn't do the water change the nitrites would have come down sooner or later and it wasn't stalled at all.

By tinkering with the cycle, don't you take a risk of not having a stable bacteria colony to handle a spike in ammonia. Shouldn't you let the nitrites come down naturally?

 

[MacDracor]

Sometimes the stalk is caused by either an excess or a lack of something. Other times it is a ph issue. Either way, a large water change can help restore the balance and allow the bacteria to do their thing.

 

[woody390]

The bacteria won't be affected by the water change they are not free floating they settle on surfaces and in the live rock and will stay there during water change

 

[Digger]

The bacteria won't be affected by the water change they are not free floating they settle on surfaces and in the live rock and will stay there during water change

You are correct. I wasn't meaning removing the bacteria. I was referencing removing the nitrite which is the food to build the second stage of the bacteria colony.

 

[Digger]

Sometimes the stalk is caused by either an excess or a lack of something. Other times it is a ph issue. Either way, a large water change can help restore the balance and allow the bacteria to do their thing.

So a condition that has changed that is not conducive to bacteria growth? That could make sense but I need to investigate that a little more.

 

[MacDracor]

Like all living things, the bacteria have requirements. If they aren't met, they can't do their thing. We tend to think of the bacteria as nothing more than filtration, but the cycle is an interesting biology lesson. Lol