High Nitrite, Help!

[audia4]

Hey all

I recently did a water change on my tank and cleaned one of the TWO externals that I have on the tank, with aquarium water. The tank has been running for months, and is cycled with no problems.

All of a sudden today my nitrite was off the charts, the water change was done only 2 days ago with the filter cleaning.

The tank is 280litres and houses a colony of 16 tropheus. Does anyone know why this may of happended so I can prevent it in the future. I havent had this problem before, as the tank has been running fine. The tropheus have been in the tank for a month.

Ammonia is 0ppm with nitrate a little higher at abour 20-40pm, normally about 10ppm.

Can someone shed some light on this please, I will be doing a water change very soon, waiting for my new water to warm to temp so i can do it.

Thanks.

edit: note, jus remembered, i did add some seachem purigen to the filter after cleaning which i had taken out 1 week ago, during a medication period. i simply washed it and put it back in, could this have caused the problem?

 

[term_22000]

Hey all

I recently did a water change on my tank and cleaned one of the TWO externals that I have on the tank, with aquarium water. The tank has been running for months, and is cycled with no problems.

All of a sudden today my nitrite was off the charts, the water change was done only 2 days ago with the filter cleaning.

The tank is 280litres and houses a colony of 16 tropheus. Does anyone know why this may of happended so I can prevent it in the future. I havent had this problem before, as the tank has been running fine. The tropheus have been in the tank for a month.

Ammonia is 0ppm with nitrate a little higher at abour 20-40pm, normally about 10ppm.

Can someone shed some light on this please, I will be doing a water change very soon, waiting for my new water to warm to temp so i can do it.

Thanks.

edit: note, jus remembered, i did add some seachem purigen to the filter after cleaning which i had taken out 1 week ago, during a medication period. i simply washed it and put it back in, could this have caused the problem?

What kind of water did you put in there? Did you use RO, or just water from the tap that you conditioned?

 

[audia4]

I have a nitrate filter which tap water goes through into a 100litre water butt, after heating it to the correct temp i add dechlor and then let it fill the tank slowly.

 

[guppi]

Im no expert but I think cleaning the filter has just change things slightly, Should be back to normal in a couple of days.

 

[audia4]

I sure hope it does return to normal in a few days, I cleaned the filter in the normal way using tank water, so this is just all a bit weird. and the even more weird thing is, i have two filters, the other i didnt even touch!