How long will Nitrites spike?

[NickK]

I'm almost 8 weeks into a fishless cycle. A little over a week ago, my nitrites went through the roof. How long will they peak? Also, will they gradually go down, or suddenly disappear?

Thanks,
Nick

[chavez720]

Not to add fuel to a fire but I have never had to deal with tank cycling with my fully planted tank. I have added 4 fully grown discus into a newly started 75 gal tank (48hrs) with no cycling.

No measureable ammonia or nitrite! Let the flame wars begin!!

[Ralph]

Hi Nick,
Cycling with fish, you get nearly a bell curve on the nitrites. You get the same general shape with the fishless cycle but there are daily spikes when you add the ammonia. To get accurate picture of your progress, you have to add the ammonia at the same time each day and test at the same time each day (right before you add the ammonia is the best time).
Eight weeks is a little on the long side but not unheard of, it's a factor of water temp, filter size and material, water movement, aeration, pH, and probably some things that I forgot. It will happen eventually though.

Hi Chavez,
How can you argue with a test kit? Since plants use ammonia, nitrites, and nitrates, it is very plausible that you could put fish in a uncycled tank. A couple things are needed though and correct me if your situation was different. You would need a low fish load. You would need a lot of plants. Those plants would have to be the kind that utilize a lot of nitrogen. And finally, those plants would have to be actively growing, and growing fast. Even with all that, I might still use an ammonia absorbing resin.
Theoretically you could have a tank with no filter at all. It would be a challenge though and possible more work than it is worth. It was all they had for years (they called them "natural" or "balanced" aquariums, also "Leiden" tanks). But we should be thankful for filters, it means that we can have more fish.

[ronrca]

One thing that I would like to mention and Im quite sure green freaks (Plants I mean) will agree with is the fact that plants do not use nitrites! Ammonia and nitrates, yes! But not nitrites! Therefore, it is essestial to cycle your tank regardless if you have plants or not!

I was also under the impression that plants do consume nitrites but aquariacentral (or whatever) proved me wrong! I thought that I would just throw that in!

Anyone else?

Btw, NIck! What is your nitrAte reading?

chavez,
How long ago did you add your discus now?

[Ralph]

Hi Ronca,
There hasn't been a lot of studies on this, the only one I have seen is on Spirodelia oligorrhiza. What they found was plants prefer ammonium to nitrites but they will use the nitrites. And they prefer nitrites to nitrates. It has something to do with the amount of work necessary to convert them into a form that the plants can use. Apparently specific enzymes are needed to convert the nitrites which isn't required for ammonium.
I wouldn't recommend that anyone try to add fish to an uncycled tank though.

[ronrca]

Hi Ralph,
I dont really know much about this scientific stuff but Tom Barr I believe his name in, goes by plantbrain on aquariacentral, specificly mentioned this in one of his posts. I had a link to the thread by they must of moved it. I cant even it it by searching.

Here is the link anyways:
http://www.aquariacentral.com/forums/html/Forum2/HTML/003195.html

[Ralph]

Sorry NicKK, we got a little off track here, and you probably don't even have plants. It's not unusual though that threads take unexpected turns. And disagreements about real basic issues are common too, it's part of having discus I think. If you haven't read it already, there is a very good thread on fishless cycles with a lot of links to other sites also.
http://forum.simplydiscus.com//index.php?board=5;action=display;threadid=1151

Ronca, I couldn't get anywhere with the link but I would like to read it though.

[NickK]

Thanks, guys. My nitrates are getting very high. Almost off the test kit. 80-160 ppm ?

Nick

[chavez720]

Roncra - 6 Discus in tank for about 3-4 days. Restarted tank after 2.5 days with out power due to an icestorm. Tank temp got down to about 50°F. No filtration or heat so all bio filtration was gone. Just restarted tank and did not even change the stagnant water that was left in the filter.

(Flame on)

I did test the water after turning the power back on and measured no ammonia or nitrites. Now I do not run a typical discus tank. It is packed full of plants, high intensity CF lighting, and CO2 injection. After restarting the tank and CO2 the plants started pearling within minutes. In my opinion the plants use up the ammonia before it can even be turned to nitrite. In fact I reguarly add 5-10 ppm of Nitrate 2 to 3 times a week to the tank for good plant growth. If I do not the tank runs close to 0 ppm Nitrate and algae takes over.

I guess I am a little impatient to wait 29 days to add fish so plants are my primary filtration!

(Flame off)

[Carol_Roberts]

Nick - do a 90% water change. Add enough ammonia to read 5 ppm, if after 24 hours ammonia and nitrIte read zero and you have a reading for nitrAtes your tank is cycled.
Carol :heart1:

[ronrca]

Nick,
Plants make a world of difference! Like you said, the plants possibly could be using up the ammonia which is great. However, imo, I would not take that chance I guess. Not with my discus. However, on the other hand in a situtation like yours, I may have no choice though! ;)