Nitrites come down on its own (no WC)- cycled?

[CxN]

I've had a tragedy with one of my tanks, which is fairly new (1.5 month old). Sudden nitrite spikes! Killed 2 newly introduced guppies. I removed my sensitives fellows to another tank, except some juvenile shrimps whom I can't catch.

I did 2x 30% water changes in 24h. 2 days later nitrites still .4ppm. I've redosed Stability everyday since (3 days).
This morning Nitrite reads less than .025

Nitrates hasn't increased (still 2-5) but I have a decently planted tank with two greedy guzzlers - Wisteria and Anacharis, they are growing like crazy with minimal ferts. So I dont expect to read nitrates unless the bacteria produces lots of it.

My question is - if the nitrites go down on its own, can I say its the work of the bacteria? And that cycling is done?

 

[Barry Tetra]

It’s either cycle is done or Anacharis absorbed them

 

[CxN]

Thanks Barry. I hope it's the first one.

 

[Essjay]

Plants take up ammonia made by the fish and they don't turn it into nitrite or nitrate. Now that the plants are growing really well they are probably taking up all the ammonia made by the fish, and the last of the nitrite made from ammonia before the plants started to grow has been dealt with by the bacteria.

 

[CxN]

Plants take up ammonia made by the fish and they don't turn it into nitrite or nitrate. Now that the plants are growing really well they are probably taking up all the ammonia made by the fish, and the last of the nitrite made from ammonia before the plants started to grow has been dealt with by the bacteria.

So it's safe to say the most likely reason my nitrite went down without a WC, is the bacteria. Like Barry mentioned I read some plants do readily take up nitrites (while most take either ammonium or nitrates) I wasn't sure mine did that.

If it is indeed a sign its entering the final stage of cycling, do you advise that i do a WC now and then add back my fishies? Or wait longer?

 

[Essjay]

Are there any fish in the tank at the moment? Re-reading your first post I couldn't decide whether you've moved them all or just the more sensitive fish.

If there are no fish in the tank, it is impossible to say whether or not it cycled as there is no ammonia going into the tank. If you put the fish back they'll start making ammonia and if it's not cycled, and the plants aren't enough to remove all the ammonia, nitrite will show again.

If there are still some fish in the tank it is probably cycled, but test every day once the rest of the fish are moved back in as there could be a mini cycle.

 

[CxN]

Thanks Essjay. Appreciate this post. Yes I had moved out the fish but to keep up with the demand of the bacteria I've been adding a bit of fish food.
Nitrites did go up a bit again, so as you've correctly pointed out, cycling isn't done. I'll start adding back the hardiest ones slowly. Also adding 1-2 airstones. And keep testing. Really appreciate your advices.