Clarifying On Fishless Cycling.

[Deus Machina]

I've read the sticky on it, and just want a little live help on it...

Been bringing the ammonia in my tank up to 5ppm, to go by the little chart card. It's too the point where this is coming down to between .25 and 0ppm in about twelve hours.

Did a 50% water change today because my nitrites were completely off the chart.

Now, as I gather, I'm supposed to be able to go from 0 ammonia, 0 nitrites, drop in 5ppm of ammonia, and have it back at 0/0 twelve hours later, correct? Not 0 ammonia, .5 (for example) nitrites around then.

 

[Miss Wiggle]

you are correct, the usual accepted point where you can say the cycle is done, is when you can drop in 5ppm of ammonia and 12 hrs later both ammonia and nitrite will read 0.

Now that being said there is some discussion about getting shot of the last bit of nitrite and how vital it is for it to be on 0. Some people have experienced it when it only drops to 0.25ppm in 12 hrs and just won't shift beyond that point, so they've taken a chance, stocked and it's been fine, have a read of the thread 'when is a cycle finished' in the scientific section for more info

 

[waterdrop]

It sounds like you are at the turning point we sometimes call "end of phase 1", "beginning of phase 3 or nitrite spike phase."

During this second phase of fishless cycling it can be good to begin doing large water changes and gravel cleanings on the weekends, as this will lower your nitrite and nitrate levels and will begin to keep your gravel clean, which is especially good if you have live plants in there. Of course you always condition the return water and recharge it with the 4-5ppm of ammonia (although actually 2-3ppm will do just fine in the first part of this second phase as 4-5ppm will just keep making huge amounts of nitrite and nitrate that can't be processed anyway. You can still eventually end up with the 4-5ppm on down the road.)

Another thing that's good to watch during fishless cycling is your pH and potentially your KH. The fishless cycling process tends to drive the pH down and if you have low KH (low buffering) then your pH may suddenly crash to a lower level and stall your cycle.

~~waterdrop~~