Plant Fertilizers Elevating Nitrites

[Badjuujuu]

I have been getting a reading of nitrites in our 10g tank for about 3 weeks now. The odd thing is Ammonia has always been 0 and Nitrates seem to be generating on a regular basis (last test they were around 20 and the previous around 5). So I was wondering is it possible the Seachem Flourish Tabs I have in the tank are either generating excess nitrogen which is being integrated directly into the cycle at a nitrite conversion point, or if the tank is still cycling and the nitrogen the ferts are providing are being used for nitrate production without utilizing nitrites?

[Iliveinazoo]

I have been getting a reading of nitrites in our 10g tank for about 3 weeks now. The odd thing is Ammonia has always been 0 and Nitrates seem to be generating on a regular basis (last test they were around 20 and the previous around 5). So I was wondering is it possible the Seachem Flourish Tabs I have in the tank are either generating excess nitrogen which is being integrated directly into the cycle at a nitrite conversion point, or if the tank is still cycling and the nitrogen the ferts are providing are being used for nitrate production without utilizing nitrites?

I don't know the ingredients of those tabs but if they release ammonium then it's possible and you may want to cut down the amount that you use. Then again it's not clear whether you are cycling the tank and the tank is only 3 weeks into its cycle, if you're cycling then you should see the nitrites fall off to zero in the next couple of weeks.

[Troender]

I don't know that brand, but some fertilizers contain nitrate.

BUT: getting nitrate readings in your tank is normal. When you have a cycled filter, the end product of what the bacteria process is nitrate. Increased nitrate level can come from fewer water changes or more fish. Or from an uncycled filter finally getting cycled. And, yes, from fertilizers that contain nitrate.

[Badjuujuu]

I probably should have elaborated on the time of the tank. It has been running for about 3 months and about was cycled. At some point it was treated with an API Ich medication and it went into a re-cycle. After all the levels looked good, Ammonia: 0, Nitrite: 0, and Nitrate: Above 0, we added a couple of Dwarf Puffers. The tank was never empty after the ich treatment, had no where else to put the otocinclus in there, is this possibly just an adjustment cycle to meet the new bio-load then? The Nitrites have never been above 0.50 and I test about every other day. I just had thought if it was doing a cycle the nitrites would go higher, but now that I am sitting here thinking if all the bacteria was established, an adjustment cycle probably wouldn't be as intense as the initial.

[Pufferpunk]

My guess is your tank is adjusting to the new bioload. Water changes getting 'trite to 0 are in order here.