Fishless Cycling in a rut?

[aklaum]

Hello all,

This is my first post. I am cycling a new 20 gallon tank with the fishless cycling/household ammonia method. I have gone with the general theory of taking the ammonia up to 5ppm and letting it get back to 0ppm and then adding enough ammonia to get it back to 5ppm. It took about 2 weeks for the ammonia to move at all. Finally one day it started to go down.

Once it hit 0ppm I added more ammonia and took it back to 5ppm. 10 hours later it was back to 0ppm. Excellent! I thought. I tested for nitrites. Off the chart. Wonderful! I thought. I did this cycle two more times and each time it went from 5ppm to 0 in about 10 hours. Go bacteria go! I thought.

Then I went for another cycle. I took it back up to 5ppm expecting the same kind of turnaround. It is now 4 days later and it has just now gotten back to 1ppm. Serious reduction in ammonia consumption speed. I tested for nitrites again. Still just off the scale of my test kit but far less hot pink than before. Maybe 11ppm?

Nothing has changed in the tank. I have it set at 85 degrees and I have a temporary powerhead installed oxygenating the heck out of the water.

I'm not sure what this means or where to go from here. What could be happening?

Also if I do get through this 5ppm ammonia cycle, how much can I stock the tank when it is complete? People have said that one of the benefits of fishless cycling is that you can fully stock the tank once the cycle is complete. Would this be true in this case or have I only simulated a few zebra danios and should only add fish slowly once the cycle is complete.

Any help would be appreciated.

 

[aklaum]

In case anyone is wondering. Below are the links to all of the articles I read on fishless cycling to try and figure out how to do it. I ended up using the method in the last article in the list. However I did not rely completely on the "Ammonia Alert" in-tank monitor. I used a more accurate ammonia testing kit.

http://www.firsttankguide.net/cycle.php

http://malawicichlids.com/mw01017.htm

http://homepage.ntlworld.com/faustus/nicoldaquaria/fishless.htm

http://www.aquatic-hobbyist.com/profiles/misc/fishlesscycling.html

http://www.csupomona.edu/~jskoga/Aquariums/Ammonia.html

 

[tropicfishman]

It may take some time to develop enough bacteria in order to dissolve and breakdown the ammonia, I've heard rumors that after a week of a fishless cycle you could put a couple fish in the tank and the levels would start to adjust to where they need to be, I've also heard that if your PH levels are off, adding fish will bring it back to where it needs to be, I don't know how true these are considering when i cycled my tank without any fish i filled it up, used a new filter cartridge, a c- 100 ammonia remover bag, chlor out, stress zyme, stress coat and kents ammonia detox and tested the PH every coule days, after about a week and a half i added fish and there doing fine, I never test for ammonia or nitrites or nitrates or water hardness, just PH. In all they ears I've had fish tanks thats all i ever did and i have prolly lost around 3 fish to misterous deaths.

 

[malkore]

You're adding too much ammonia. once nitrites are detected, you can drop ammonia dosing down to 2-3ppm. 5ppm can actually be too much, and slow the growth of nitrafying bacteria...the final stage of the cycle...and the longest to begin with.

 

[TomK2]

Once your nitrosomas bacteria (ammonia eaters) are establishing themselves, and your ammonia levels go to zero, each ppm of ammonia you add from then on to keep your nitrosomas alive and thriving adds on top of the very high amount of nitrite you are waiting to be consumed. Thus, once your ammonia goes to zero, Adding 5ppm per day will cause you to end up with way high nitrite. Since Nitrobacter (nitrite eaters) grows slower than nitrosomas, the higher the nitrite hill you make, the longer the cycle. I would cut back on the amount of ammonia you add daily to be somewhere in the range of 0.5 to 1 ppm per day. I would do PWC's to bring the nitrite level down to below 5 ppm. Very high nitrite levels (>12ppm) can interfere with the ammonia test as well, making you think the ammonia level is rising. Also, a low pH, below 6.5, can really stall a cycle.

So, PWC to bring nitrite down, add less ammonia each day, and if your pH stays up you will be done in a few weeks, hopefully less.