Is my cycle done?

[blackandwhite]

I have been cycling a 90 gallon for about two months now and I am now wondering if my cycle is done. My tank cycles 4ppm of ammonia to zero in 24 hrs and nitrite and nitrate to zero in about two days. I've been at this rate for about two weeks now, but the process is not getting any faster. Does everything need to get down to zero for cycle to be done? Or is this an acceptable rate?

 

[BBradbury]

bla...

Ammonia and nitrite must be zero. Nitrates are the end result of the nitrogen cycle, so they can be upwards of 40 parts per million, with no harm to most aquarium fish you get at the local pet store. If this is the case with your tank, you're ready to add some hardy fish species like Guppies, Platys, Swordtails, Rasboras, White clouds and Danios. It's best to use these when starting out, because they're relatively tolerant of mistakes beginners tend to make in tank management.

Test the tank water frequently and if you see traces of ammonia or nitrite, remove a quarter of the tank water and replace that with the standard water treatment. I use Seachem's "Safe", but there are others.

B

 

[blackandwhite]

bla...

Ammonia and nitrite must be zero. Nitrates are the end result of the nitrogen cycle, so they can be upwards of 40 parts per million, with no harm to most aquarium fish you get at the local pet store. If this is the case with your tank, you're ready to add some hardy fish species like Guppies, Platys, Swordtails, Rasboras, White clouds and Danios. It's best to use these when starting out, because they're relatively tolerant of mistakes beginners tend to make in tank management.

Test the tank water frequently and if you see traces of ammonia or nitrite, remove a quarter of the tank water and replace that with the standard water treatment. I use Seachem's "Safe", but there are others.

B

Thank you. I've got some fish in there now. It's been about two hours and they all were interested in the food I put in.

 

[Fresh2o]

The zero nitrate is not something you would see in a cycled tank.
At this point I would continue to monitor all three parameters and perform water changes on a regular basis.

 

[blackandwhite]

The zero nitrate is not something you would see in a cycled tank.
At this point I would continue to monitor all three parameters and perform water changes on a regular basis.

When I put in ammonia the nitrite and nitrate both spike up by the time ammonia is back down to zero. And then by the next day they are both down to zero. Seems to me that's a good thing. Cause for a long time the nitrates were massive high even with water change.

 

[drm315]

When I put in ammonia the nitrite and nitrate both spike up by the time ammonia is back down to zero. And then by the next day they are both down to zero. Seems to me that's a good thing. Cause for a long time the nitrates were massive high even with water change.

I didn't know you could put ammonia in a tank that already has fish in it...

 

[Fresh2o]

I didn't know you could put ammonia in a tank that already has fish in it...

You can't (well, you can, but that would not be safe for the fish).
I believe the ammonia was added early in the cycle BEFORE the fish were added.

 

[blackandwhite]

You can't (well, you can, but that would not be safe for the fish).
I believe the ammonia was added early in the cycle BEFORE the fish were added.

Yes the ammonia was added to cycle the tank before the fish.