Cycling question

[jenpedi]

I am cycling a 90 gallon tank. Today the ammonia dropped to zero, the nitrites are off the chart, and I am checking the nitrates in a few minutes. yesterday they were at about 20. After finding the ammonia at 0 this morning, I added a little more than half the amount of ammonia it took to raise the ammonia level to 5.

Has the ammonia dropping down to 0 done any damage to the bacteria (starved them?).

Do I need to be adding half the orginal amount of ammonia OR do I need to be keeping the ammonia level at any specific reading?

So now I am waiting for the Nitrites to drop to zero, correct?

And after the cycle, how much ammonia do I need to be adding to the tank until I get fish? Or what level of ammonia should I maintain?


Thanks in advance!

[Sasquatch]

Well, it looks like your fishless cycle is coming along nicely.

Right not, keep adding enough ammonia to get the levels to around 2-3 ppm. Check everyday to make sure that the levels drop to 0 and once both the ammonia and nitrites drop to 0 ... you're done!

Don't worry about starving the bacteria, as long as you keep adding ammonia, they'll be fine.

As for when the cycle is finished, keep adding the same amount of ammonia each day (2-3ppm worth) until the day before you get your fish. Do a large water change to get the nitrates down before you go get your fish and after that, acclimate as normal. Make certain not to disturb the gravel too much or change any of the filter media ... that'll set back the cycle. Also, add dechlorinator before adding the tap water! Otherwise, the chlorine will kill of some bacteria and set back the cycle.

Keep an eye on the levels for a few days, just to be certain, but adding your fish shouldn't cause an ammonia/nitrite spike.

Congrats, good luck and keep us posted.

[jenpedi]

Well, it looks like your fishless cycle is coming along nicely.

Right not, keep adding enough ammonia to get the levels to around 2-3 ppm. Check everyday to make sure that the levels drop to 0 and once both the ammonia and nitrites drop to 0 ... you're done!

Don't worry about starving the bacteria, as long as you keep adding ammonia, they'll be fine.

As for when the cycle is finished, keep adding the same amount of ammonia each day (2-3ppm worth) until the day before you get your fish. Do a large water change to get the nitrates down before you go get your fish and after that, acclimate as normal. Make certain not to disturb the gravel too much or change any of the filter media ... that'll set back the cycle. Also, add dechlorinator before adding the tap water! Otherwise, the chlorine will kill of some bacteria and set back the cycle.

Keep an eye on the levels for a few days, just to be certain, but adding your fish shouldn't cause an ammonia/nitrite spike.

Congrats, good luck and keep us posted.

Thanks for all the help! This morning I brought the ammonia back up to 3 ppm. I tested everything again tonight.

Ammonia 1
Nitrites 5
Nitrates 5-10

The Nitrates had been up to 20+ but now they are lower.

Is this normal for the Nitrates?

[SkinnyChicken]

You probably wouldn't expect the nitrate level to drop unless you changed some water but the whole cycle process can involve a lot of factors and it isn't until your ammonia and nitrite levels are zero and you fully stock your tank that it becomes easier to predict how your nitrate level will rise.

As Sas has already mentioned above, your cycle is coming along very nicely. Congrats.

[cabrego]

I will chime in here, In most of the tanks I have cycled at the end of the cycle ALL parameters drop to zero. This includes nitrates, while my cycling has actually been with fish in the tank, I know there are a number of folks on the AC who have also experienced this too. So it is not unusually for nitrates to drop to zero, I should also mention that I did no water changes during my cycling process. Therefore, nitrates could not have been diluted. I have posted a threads on here a couple of times asking the question: "what causes nitrates to drop to zero?" I have had mixed responses, and I am still not certain what the phenomena is..

[jenpedi]

I will chime in here, In most of the tanks I have cycled at the end of the cycle ALL parameters drop to zero. This includes nitrates, while my cycling has actually been with fish in the tank, I know there are a number of folks on the AC who have also experienced this too. So it is not unusually for nitrates to drop to zero, I should also mention that I did no water changes during my cycling process. Therefore, nitrates could not have been diluted. I have posted a threads on here a couple of times asking the question: "what causes nitrates to drop to zero?" I have had mixed responses, and I am still not certain what the phenomena is..
No water changes or topping off the tank so far.

So if the nitrates drop to zero I will not need to do a water change at the end correct?

[cabrego]

That sounds fine to me.

[Sasquatch]

Looking good there Jenpedi.

As for the nitrates dropping to 0 ... that's the first I hear of it. If it happens, double check your readings, but if it's the case, there shouldn't be any problems introducing fish. I'd still do a partial water change, just to get rid of anything else that may have built up.

As far as nitrates dropping ... there are a few ways, but they're usually not sufficient to cause a major drop in most tank. Plants are an obvious first answer, but unless it's very heavily planted, it's usually not sufficient to drop the levels to 0. Another phenomenon is the production if nitrogen gas (N2), but that requires anaerobic conditions in the substrate ... something most people try to avoid when cycling to encourage bacterial growth (which need aerobic conditions).