an anal question concerning cycling

[shar]

Hi there,

our 120 gallon is finally starting to cycle(fishless,with seed from our 35 hex) on Monday the ammonia dropped to 2 ppm and has each day since(after bringing back up to 5ppm),and last night we had some nitrites, so here's the anal question; is it important to wait 24 hrs to test for ammonia and then add the amount to bring it back up to 5ppm?
I tested this am(about 10 hrs.after adding ammonia) and it was already down to 2ppm, so I wasn't sure if I should add ammonia at that point or wait until 5:30 pm when we usually test the water.
and am I thinking about this too hard?

Thanks,

Shar

 

[N8DOGG]

cycle

I may be way off base but why would want to add nitrites? to speed the cycle? I would just buy some Zebra Danios and put them in the tank and let it cycle for a few days and then re-test for amonia. you want the amonia to be zero, doing some water changes will also help this along.

 

[TKOS]

Shar you are doing fine. Adding danios is silly for a 120 gallon tank as it would only lead to a tank cycled for a couple of danios.

Essentially as long as there is any ammonia present then there is too much for the current bacterial load to handle. You really just need to make sure that the ammonia levels do not drop to zero before the nitrites drop to zero and the nitrates start showing up. When the tank can go through 5 ppm of ammonia in 24 hours and also show zero nitrites with nitrate production then you are all set. Sounds like you are well on your way.

24 hours is a general rule of thumb, don't worry about being too anal. Just make sure when you add fish that there is no ammonia or nitrites present and add fish within 24 hours of the last ammonia feeding or the bacteria will start to die off a little bit.

 

[OrionGirl]

No, adding ammonia is fishless cycling--you never expose the fish to toxic spikes, and establish enough bacteria to fully stock the tank, rather than going through many mini-cycles with each fish addition.

I would wait the full 24 hours. Part of this is based on slowing the production of nitrite--these colonies develop more slowly than the ammonia consumers, and by adding more ammonia every 10 hours, you are effectively increasing the titer and that means you'll need larger colonies to sustain the load--which is already higher than a well-stocked tank will produce anyway.

 

[shar]

Thank you for your responses, we'll just continue the course.
glad the cycling is moving along!

Regards,

Shar