Still Cycling - Uncertain Of Some Of The Results

[NewBea]

Hi,

I've already had some advice regarding my fish-in cycling about a week ago.

(thread below)
http/www.fishforum...d/#entry3449506

The ammonia stayed nice and low even though I stopped the daily/2 daily water changes.
4 days later (17/11) the nitrite levels started increasing - I thought "great the cycle is kicking in now nicely" and I just returned to the daily water change to make sure the fish don't suffer from nitrite.
Here are the readings for the few days after:
Date.........ammonia........nitrite.......nitrite after w.change.....nitrate
17-Nov........0-0.25..........0.25....................0.00
18-Nov........0-0.10..........5.00..................2.0-5.0...................40
19-Nov........0-0.10........2.0-5.0..................0.50.....................20
20-Nov........0-0.10..........0.00
21-Nov........0-0.25..........0.00................................................10

As you can see the nitrite had spiked but I kept it under control with 25% water changes. (I do use dechlorinating agent, tetra safe start and tetra easy balance products; and of course match water temperature) Nitrite levels after water changes shown in the table too - ammonia was also tested but didn't show any difference. I didn't do any water change today and yesterday and the nitrite levels reduced to 0 on their own (hopefully sign of the bacteria working).

A few questions I need help with:
- First of all I struggle a little bit with the ammonia readings. I do have an API master kit but every time I test ammonia it's not a clear cut 0 for me - always seems to be slightly in between 0 and 0.25 which is the next colour on the scale. Is it possible that the ammonia hasn't reduced to all the way to 0, or is it just me now being able to differentiate between the colours properly? Is it possible that after the nitrite levels have increased and returned to 0 the ammonia would be still increasing?
- Do the levels in the table make sense/look ok? Is this an expected result? It just seems that the nitrite had spiked and reduced extremely quickly - at least compared to the ammonia levels before.
- Do products tetra safe start and easy balance make any difference in your opinions?

Thanks,
Beatrix

 

[bmonki]

ok, firstly ammonia is constantly being produced. so yes, even when you have a nitrite reading you can still have an ammonia one.

secondly, for a nitrite spike, 25% changes are just not enough, you need to be doing a minimum of 75% with a fish in cycle. anything over 0.25 nitrite can kill your fish.

 

[NewBea]

Thanks bmonki, I will keep that in mind for the future. The fish seemed happy and had a normal behaviour and the levels were going down nicely but next time I add fish and the levels start spiking I will definitely do larger changes.

Regarding the ammonia and the cycle in general - so when people say that all levels need to be zero (ammonia, nitrite and nitrate) does it ever happen then? If the fish keep being fed and poo and pee keep releasing ammonia then what are the normal levels?If the only acceptable ammonia level is 0 then how can I achieve it?

 

[fluttermoth]

First of all, nitrate doesn't need to be at zero. Anything up to about 40/60ppm of nitrate is acceptable for most fish.

There will always be ammonia present in the tank, between the fish producing it and the filter bacteria dealing with it, but if the filter is cycled and has enough flow for the tank, the ammonia will be of such a low level that it won't show up on your tests. Same for the nitrite.

The bacteria convert the ammonia, first to nitrite and then to nitrate, so the nitrate level will gradually rise all the time. That's one of the main reasons for regular water changes; to stop the nitrate getting too high.

 

[NewBea]

Thanks very much, Fluttermoth - it all makes sense then.