# Cant get rid of nitrites :- Wierd



## Marshes (Apr 14, 2005)

Fish Tank :- 6 x 2 x 2
Occupants :- 2 large oscars , 2 large Fenestraum (breeding /w babies), 1 convict, 3 kribensis 
Filtration :- 2 external filters. 1200lph, 2400lph im sure flow rate is lower than stated.
Tank setup for :- over 6 months easily.
substrate :- sand

Tests :-
Ammonia :- 0
nitrite :- .5 ppm
Nitrate :- 40 ppm

I have tested my water straight from the tap and everything is ok. I do weekly 15ish % water changes.

What am i missing.... I have been in fish for quite some time and i just dont know why i cant get rid of the nitrites!

Any ideas would be very much appreciated.


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## convictkid (Jul 28, 2004)

Its simple the bio load is to much for the bacteria to catch up with, your probably just over stocked or need more bio filtration.


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## Toby_H (Apr 15, 2005)

Your stock list should not be overburdening your bio-filtration on a 180 gal tankâ€¦

High nitrates suggests a strong bacteria colonyâ€¦ High (any) ammonia suggests something recently damaged the bacteria colonyâ€¦ High (any) nitrites are much more rare and are typically seen during a short period during â€˜cyclingâ€™.

I am not personally aware of anything that will not damage ammonia-to-nitrite bacteria but will damage nitrite-to-nitrate bacteriaâ€¦

My first thought is that your bacteria colony crashedâ€¦ and is in mid process of reestablishing itself.

How long have you had this low nitrite reading? Has it consistently remained around .5? Or has it spiked and settled down?

I am 1000% convinced there is absolutely no chance that you tank simply cannot hold enough bacteria to handle your bio-loadâ€¦ so I can only imagine that something is challenging the bacteria causing it to die off as soon as itâ€™s produced, therefore it doesnâ€™t expand to dissolve/eat all the wasteâ€¦

But as to what that could beâ€¦ Iâ€™m not sureâ€¦


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## lloyd (Aug 24, 2005)

IMO: retest in a week or two (depending on bioload), prior to any further water changes. if your nitrates are accumulating, then your nitrite test result is likely false. if your nitrates hold steady at 40ppm, then your tank has/is experiencing a spike or crash. nitrobacter are sensitive to sudden ph rise, aggressive cleanings, chlorine/chloramines, and gram negative medicines. 
it is my theory that tanks crash in reverse direction. so, if your cycled tank tests a (+) spike in ammonia, you likely just missed the nitrite phase of collapse.


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## Marshes (Apr 14, 2005)

Day 2 of the oddities

Ammonia :- 0ppm
nitrite :- .25-50ppm
nitrate :- 20ppm
ph :- 7.4

How could nitrates be dropping without water changes? I put in a few plants yesterday to try to help with the nitrites but they total 3 mid size anubis. I cant see them having that sort of affect on the nitrates.

This is all getting abit beyong me but i will keep testing and reporting back.
Today i normally do water changes but i will hold off and let the nitrates do their thing.

The only thing that occurs to me is that when i normally do weekly water changes i just stick the hose directly into the tank and put in a cap full of chlorine remover. Perhaps this is causing the crashing ?


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## Toby_H (Apr 15, 2005)

Marshes said:


> The only thing that occurs to me is that when i normally do weekly water changes i just stick the hose directly into the tank and put in a cap full of chlorine remover. Perhaps this is causing the crashing ?


This is how I've done it for several years with no issues... I've always (as long as I can remember) used Prime for conditioning...

I personally would not forgo the water change this week. Although the information you will gain from watching the nitrates is important, keeping your fish in as close to nitrite free water is more important (in my book).

I would do a healthy water change to reduce all the pollutants... then see what rises and track it's pace...

I would also try to add mature media from another aquarium. Although it would be wonderful to figure out the cause of the problem, fixing the problem is the ultimeate goal.

Adding Bio-Spira or the like is also an option to consider (I'm familar with these products but have not used them personally).

regardless of what method(s) you use, keep a close eye on the numbers afterwards. If something works as a quick fix I would still watch the numbers closely (test about twice a week) for a month or two afterwards to ensure things remain stable. If you can watch them wonder off course you may be able to pinpoint the cause easier...

Best of luck...


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## lloyd (Aug 24, 2005)

i would choose to add sodium chloride (salt) to detoxify nitrite, and allow the tank to continue through it's cycle issues. nitrite is not an 'overnight killer' at low levels. a close watch of gill color (brown is bad) and gill function levels (rapid gill movement, clamped gill, gasping at surface is bad) can help to calm a nervous keeper through this stage. if your test results are good (your lower nitrate result would force me to suspect accuracy of all), then the rise in nitrite is a good sign of ammonia processing, and indicates a cycle moving forward. 1 level teaspoon/5 gallon dosing of salt, will be sufficient for low nitrite exposure, and it will not interfere with test results. IMO.


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## Marshes (Apr 14, 2005)

Hi Guys, 
I appreciate the differing opinions so i combined the two.

I added salt to the tank and topped the tank off with water (5%).

Before i did this i did a water check

Day 3 of oddities

Ammonia 0ppm
Nitrate .25-50ppm
Nitrate 20ppm

We havent really got any other tanks i could take filter media out of. 
How long should it take for the nitrites to go away if nitrates are currently 20ppm ?


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## herb (Mar 23, 2003)

how old is your test kit, as in when was it made, not how long you have had it, if it is old you can get mixed results, this may be problem just another thing to check out.

herb


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## Marshes (Apr 14, 2005)

herb said:


> how old is your test kit, as in when was it made, not how long you have had it, if it is old you can get mixed results, this may be problem just another thing to check out.
> 
> herb


Hi Herb,

That thought crossed my mind as well. I imagine the test kit is quite old. (This is our work fish tank, so works test kit ).
I checked one of the other fish tanks we had at work and the nitrites tested normal.


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## Marshes (Apr 14, 2005)

Day 5 oddities

nitrites :- .25ppm
nitrates :- 10ppm

How long should this crash/mini cycle be going on for ?


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## Marshes (Apr 14, 2005)

*Day 6 of oddities*

Nitrite

.25 - .50ppm

Help! How could the tank still have nitrites.


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