nitrite? please read

[LithoMan]

Hi All

i have this 1 tank its about 250L I am running a fluval 405 also a big hang on filter with pretty good media in it... the fluval is one of my oldest filters i have not 100% when was the last time i changed the sponges in the filter.. but clean it every 4-5 months...

now this particular tank i have notice always ends up getting big spikes of nitrite my fish started to die checked water all looked ok more died and checked water today and the nitrite was high had gone dark blue/purple colour on api test kit....

any thing you can think of why this particular tank would always get nitrite in it..... i had 20 demansoni and about 4 bristle nose in tank once a week i do a 10% water change with gravel cleaner and then put tap water back in with seachem safe -- seachem lake salt also seachem buffer and on ever second water change i add a small amount of bacteria(stability or the api version stress zyme)

before that i had about 7 dimi comps in it 10-17cm plus the bristlenose and same thing happend and they died.

just can't work out what is wrong the filter spongers? the media in it ? no idea please any advice will be great..

thanks

[mathobes]

How much, how long has it been in use and what kind of bio media are you using? Are you using any chemical filtration like carbon etc?

Also when was the last time you tested your tap water?

[LithoMan]

i tested the water for ammonia not nitrite i will 2moro .... but always its same tank ... Hmmm i need to check if it has carbon in that filter could that cause nitrite?

[mathobes]

From my understanding carbon that is all used up (it has a really short usage time) leaches bad stuff back into tanks, which can kill bacteria, which will create mini cycles.

[mathobes]

^^^^^ I'm not 100% sure on this, maybe someone else can chime in. I do know that it leeches stuff bck into water but not fully sure on the minicycles.

[cpfc]

Nitrite is caused by a lack of bacteria to process it to nitrate but you already know that. A common cause of spikes is an overzealous filter media washing routine or one that washes the media in plain tap water. Other causes include new fish, dead fish or other dead matter.

How do you clean your filter?

Nitrite emergencies can be treated with salt and or prime. Google will help you on doses.

I still suspect you bio media bacteria is getting killed.

[Josh]

I would up the water changes to 25% for a few weeks and see if that helps. I would have a guess and say that your filters arent holding enough bacteria to cope with the bio load. I would be interested to know what media you have in them.

[mcloughlin2]

Carbon leaching back into the tank won't cause nitrite spikes. Nitrite spikes occur when their is not a suitable population of bacteria to cope with the bioload of the tank.

Solutions for this would be upgrading the filter, putting some higher quality biological media in the current filter or lowering the stocking levels in the aquarium.

Have you tested the water used for water changes? It may be possible there is a nitrite reading there?

[Matthew]

Hi All

i have this 1 tank its about 250L I am running a fluval 405 also a big hang on filter with pretty good media in it... the fluval is one of my oldest filters i have not 100% when was the last time i changed the sponges in the filter.. but clean it every 4-5 months...

now this particular tank i have notice always ends up getting big spikes of nitrite my fish started to die checked water all looked ok more died and checked water today and the nitrite was high had gone dark blue/purple colour on api test kit....

any thing you can think of why this particular tank would always get nitrite in it..... i had 20 demansoni and about 4 bristle nose in tank once a week i do a 10% water change with gravel cleaner and then put tap water back in with seachem safe -- seachem lake salt also seachem buffer and on ever second water change i add a small amount of bacteria(stability or the api version stress zyme)

before that i had about 7 dimi comps in it 10-17cm plus the bristlenose and same thing happend and they died.

just can't work out what is wrong the filter spongers? the media in it ? no idea please any advice will be great..

thanks

G'day

The cycle is Ammonia -> Nitrite -> Nitrate

As you have unfortunately discovered Nitrite is particularly dangerous to fish. You absolutely need bacteria to convert it between each type of chemical.

I suggest that you start 25% - 40% water changes.

Never do a filter clean on water change day and never do both filters on the same day. Only clean your filters using tank water as normal tap water will kill off the all important bacteria.

I would suggest that you use aged water for you water changes, all you need is a plastic water barrel and you are away. Reason; the chloramine in the water even with safe added from tap water can rapidly decrease the bacteria level in the filters.

As Josh asked what type of filter media do you have?

Cya

Matthew

[LithoMan]

will look in the filter maybe a few pics also after work 2moro

thanks for your help All

[CThompson]

The nitrogen cycle has been mentioned and this as others are saying is your problem. The REAL problem is to sort out why.

For one, clean your sponge more frequently than 4-5 months. Are these sponges mechanical or biological filtration? If biological, then ONLY clean in water syphoned from the tank. Biological media must be treated as you would a live fish, though don't be afraid to treat it rough when cleaning in tank water, but don't let it dry out. The rest of the mechanical side of the filter can be cleaned in tap water. Following these guidelines there is no issue with cleaning a filter and water changing on the same day, though other fish keepers don't like to do this, I have done it for 40 years without issue.

Take out at least 1/3 of the water when changing, and as mentioned by others, preparing the new water in advance is a better idea than sticking a hose or pouring a bucket of water into it. If the water change water is fully prepared including heating larger water changes can be done safely, but 1/3 is fine, 10% is too little.

Your post was devoid of much information

[mattrox]

I use fluvals. As the sponges get clogged up two things happen:

1) the flow rate slows

With a slow flow rate less ammonia and nitrate are processed, this leads to a decline in bacterial numbers, and therefore even less ammonia and nitrite is processed.... a vicious cycle.

2) patches of sponge are unable to support bacteria (clogged or lack of oxygen)

Not enough bacteria mean you can't process nitrites/ammonia.....

You need to clean the fluval's sponges a minimum of once a month if you have a heavy bioload.

[polecat]

Did you check the water you put into the tank. The last water change I did cost me over $150 dollars in fish. The water did smell a bit and I did not think anything of it. Over the next three days I lost fish. Check of the tank water said everything was not good. Check of the tap water said everything was really bad! I always check the tap water now before doing anything.