Fishless Cycle

[fishygurl]

A couple of days ago, when i added 2 ppm of ammonia it was back down to 0 in 24 hours. Now it goes to 1 but it never seems to get all the way to 0. The nitrites are still off the chart though. Why is the ammonia not going down?

 

[Jchillin]

What are your nitrite readings and have you tested for nitrates yet?

 

[TomK2]

Well, you have been at it long enough to get nitrites, so you can add less ammonia from now on. Once your ammonia goes to zero in 24 hours, you do not need a daily dose of 2ppm to grow the ammonia eaters. I would go to the dose that would have been 0.5 to 1 ppm of ammonia before you had nitrites. The more ammonia you add once it is being converted to nitrite, the higher the nitrite spike will be.

So, if nitrites are off the chart, you have a lot of nitrite, and are waiting for the nitrite eaters to catch up. Just feed enough ammonia to keep the ammonia eaters growing, about 0.5ppm (per day if it goes to zero in 24 hours) should do, or at most 1 ppm. Things that impair ammonia eaters are low pH. Below pH of 6.5, nitrification is severely impaired, and it stops at pH of 6.0. I do not know if very high nitrite levels can impair ammonia eaters, but if your nitrite is off the chart, a PWC can't hurt. Nitrite of 2 to 5 ppm will grow your bacteria. Likewise, if your pH went down, a PWC can help bring it back up.

Finally, extremely high nitrate levels (>100?) can effect nitrite tests, since some of the nitrate will react. Along the same lines, very high nitrites can make you think your nitrates are higher than they are, since the nitrate test measures the amount of nitrate you have by how much nitrite it can be converted into. And very high nitrite (12ppm?) can show up on a salicylate (two bottle) ammonia test, so perhaps your ammonia level is really high nitrite interference? If this seems confusing, check out: http://home.comcast.net/~tomstank/tomstank_files/page0018.htm

I bet you have "high nitrite" interference on your ammonia test.

 

[malkore]

What brand of test kit? Are you adding anything else to the water like stress coat or something?

Some dechlorinators convert ammonia into ammonium, which causes half of all ammonia test kits to still read ammonia.

(just brainstorming)

 

[fishygurl]

AquaPlus water conditioner
Nutrafin test kit

 

[TomK2]

Well, try some PWC's to get the nitrite levels in the 2 to 4 ppm range. Add a lesser amount of ammonia, and recheck the next day. While I am not certain, I bet your ammonia reading will go to zero, as long as the pH is above 6.5. Run all your tests, pH, ammonia, nitrite, and nitrate and tell us what you get.

 

[fishygurl]

Ph 7.6
Ammonia 1.2
Nitrite 1.6
Nitrate 50

A question about the nitrate readings. I have heard that nitrite can cause false nitrate readings. Is this true??

 

[Zagz]

Yes nitrite can cause false nitrate readings. You are getting there though.

 

[fishygurl]

I kind of made a mistake with the adding ammonia thing because i kept adding 2 ppm every time it was down to 0 but know ive figured out that if i add too much ammonia the nitrate bacteria will never catch up so know im just adding a little mabye .5 so im hoping that the nitrite will start to come down soon.

 

[fishygurl]

I just noticed that TomK2 told me to do that before I should have listened!

 

[fishygurl]

I have a question about my nitrate test. After five minutes, (How long the instructions said to wait) it read about 50 but after about 30 minutes it looks like about 20.... Why is this, and what reading is correct? Its a nutrafin test kit by the way.

 

[TomK2]

Nitrite and nitrate can interfere with each others tests, and even ammonia tests too. But only at extrememly high levels. The thing about the nitrate test is that the AP test kit measures the amount of nitrate by how much nitrite it can be converted into. Thus, the first bottle of the nitrate test converts the nitrate into nitrite, the second bottle measures the amount of nitrite. So when you do a nitrate test, you are really getting the amount of nitrate plus nitrite in your tank. Normally, this does not matter, since the nitrite levels is usually very low compared to the nitrate. For example, 1ppm of nitrite doesn't throw off a nitrate level that is 25 ppm. But if you were early in your cycle, and your tank started out with zero nitrate, and you now have 5ppm of nitrite, a reading of 5ppm of nitrate could just be the nitrite, not nitrate. Once your tank is established, your nitrite readings should be undetectible, so that the nitrite will not interfere with your nitrate test.

 

[TomK2]

If the test kit says to read it at 5 minutes, thats what I would do. I haven't seen fading or changes over time in the tests I have done, but perhaps I will look for this next time.

 

[fishygurl]

i havent added any ammonia for atleast a week, because nothing seems to be changing. The ammonia has gone down a little, but only from 1.6- 0.6 over a whole week, the nitrites are steady at 1.6 and the nitrates are still at 30. Its been over a month and im starting to get impatient. Do you think i should add more ammonia or do a water change or something? I dont know.

 

[TomK2]

Bummer. But be patient, it will come. A slow cycle can be a very frustrating thing. I am surprised your ammonia isn't going down, considering you have nitrite formation. You can keep the ammonia level higher if you want to, but I am not sure it will speed things up.