Fishless Cycle - Nitrite Disappeared!

[richw]

Hi all,
 
Started a fishless cycle 8 days ago. I have a 200 litre tank with water at 26c, live plants and a 1800LPH filter. The filter came from another tank but was out of water for a couple of days before using, so whether or not the bacteria survived is questionable..
 
Started the cycle by adding 2ppm of Ammonia, then by day 3 it had dropped to 0.5ppm. At this point I started adding 2ppm of Ammonia daily (because it was dropping to <0.5ppm every day). Started to see low levels of Nitrite but it hasn't really gone up much, it's hovered around 0.15-0.25ppm for a few days now, and I've just done todays test and it's at 0ppm!
 
So what's happened? Has the cycle actually started? Are the plants using up all the ammonia? Something else?
 
Any advice would be appreciated!
 
Day 1
Ammonia - 2ppm
 
Day 2
Ammonia - 1ppm
Nitrite - 0.25ppm
 
Day 3
Ammonia - 0.5ppm (topped up to 2ppm)
Nitrite - 0.1ppm
 
Day 4
Ammonia - 0.25ppm (topped up to 2ppm)
Nitrite - 0.15ppm
 
Day 5
Ammonia - 0.5ppm (topped up to 2ppm)
Nitrite - 0.25ppm
 
Day 6
Ammonia - 0.25ppm (topped up to 2ppm)
Nitrite - 0.15ppm
 
Day 7
Ammonia - 0.25ppm (topped up to 2ppm)
Nitrite - 0.15ppm
 
Day 8
Ammonia - 0.15ppm (topped up to 2ppm)
Nitrite - 0ppm
 

 

[Blondielovesfish]

Test for nitrate, if there's some nitrate then the cycle has started.

 

[eaglesaquarium]

Its most definitely 'started'.  Its just not done yet.

 

[richw]

Just tested for Nitrate - it's at about 30ppm at the minute. What's confusing to me is that there's no nitrite at all.. if anything surely at this stage it should only be starting to increase!

 

[eaglesaquarium]

It could be that you have more nitrite bacs right now.  Any plants???

Just reread and see that you are using "established" media, even if it had been dormant for a while.  You are almost done, I do believe.  
 
Plants can use up ammonia, especially stem plants. 

 

[TwoTankAmin]

Almost done for sure. If you test 0/0 24 hours after the most recent addition to 2 ppm, you are cycled.
 
What is dry you or me is not in the bacterial scale. In their biofilm they are buying time in terms of drying out. They may not have been at full strength but even at 1/4, they can ramp up in a matter of days.
 
A major factor in a rapid cycle is having the nitrite oxidizing bacteria there at the outset as well as the ammonia oxidizers. This removes most of the lag.
 
The plants are using some of the ammonia as well as some of the nitrates which otherwise would be noticeably higher.

 

[richw]

Thanks all - didn't realise it was so far along the cycle, didn't even think that the nitrite spike wouldn't happen because of the existing bacteria..
 
It turns out my reading of Nitrate at 30ppm was actually at around 120ppm! I'm colourblind and absolutely useless at identifying shades, I let my girlfriend double check the results and see how far off I was!
 
Sure enough, checked last night and both Ammonia and Nitrite were at 0ppm. I'll continue topping up the ammonia to 2ppm till the weekend and then see about adding some fish! Now it's just working out the best order of adding them to the tank..

 

[the_lock_man]

Almost done for sure. If you test 0/0 24 hours after the most recent addition to 2 ppm, you are cycled.
 
What is dry you or me is not in the bacterial scale. In their biofilm they are buying time in terms of drying out. They may not have been at full strength but even at 1/4, they can ramp up in a matter of days.
 
A major factor in a rapid cycle is having the nitrite oxidizing bacteria there at the outset as well as the ammonia oxidizers. This removes most of the lag.
 
The plants are using some of the ammonia as well as some of the nitrates which otherwise would be noticeably higher.

 
I agree. Clearly the majority of the bacteria survived the few days out of water. If you are using the API kit to test your water, please bear in mind that the ammonia test can be difficult to distinguish 0.25ppm from 0ppm.

 

[richw]

 

Almost done for sure. If you test 0/0 24 hours after the most recent addition to 2 ppm, you are cycled.
 
What is dry you or me is not in the bacterial scale. In their biofilm they are buying time in terms of drying out. They may not have been at full strength but even at 1/4, they can ramp up in a matter of days.
 
A major factor in a rapid cycle is having the nitrite oxidizing bacteria there at the outset as well as the ammonia oxidizers. This removes most of the lag.
 
The plants are using some of the ammonia as well as some of the nitrates which otherwise would be noticeably higher.

 
I agree. Clearly the majority of the bacteria survived the few days out of water. If you are using the API kit to test your water, please bear in mind that the ammonia test can be difficult to distinguish 0.25ppm from 0ppm.
 

Good tip! I'll keep topping up the ammonia for the rest of the week, and then on Saturday I'll do a large water change to get rid of the nitrates and then go to buy some fish. I'll take some water with me to get an accurate reading from the LFS just to make sure everything is at 0!

 

[Blondielovesfish]

If you do take some water to your LFS to get tested, make sure to get the exact results as LFS's often just say "everything's fine" or, will say it isn't and try to get you to buy something to fix the "problem"

 

[richw]

If you do take some water to your LFS to get tested, make sure to get the exact results as LFS's often just say "everything's fine" or, will say it isn't and try to get you to buy something to fix the "problem"

Ha, why doesn't that surprise me. I'll definitely make sure I get the results written down so I can make a note of them in my logbook!

 

[the_lock_man]

Personally I wouldn't bother taking your own water. The LFS don't use any tests that are significantly more accurate than those available to you and I (ie, that they sell). Some of them use the paper strips, which are significantly less accurate.

 

[eaglesaquarium]

What he said!!! ^^^

 

[richw]

Oh, I presumed they'd have accurate electronic sensors or something! If they're just using chemical drop tests I won't bother.

 

[TwoTankAmin]

A digital ammonia test system runs $2,000-$4,000 and the best are more. Even a good "manual" one runs over $80. LFS/LPS would never spend that.
 
You do not need to add ammonia every day to keep the bacteria up to speed. In your tank, just adding 1 ppm every 2-3 days would work fine.