Cycle completed, and then reversed

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V

vaypourus

Feeder Fish
MFK Member
Sep 2, 2009
174
2
0
Rotcore, NY
This is an interesting one.

Started to cycle my 180 with help of some pre seeded media from one of my other tanks. Pure ammonia was added to the water, and the temp jacked up to about 84* to speed up the cycle. I started testing for ammonia after about a week into the cycle. After about 2-2 1/2 weeks, ammonia started to get removed. At one point I tested for ammonia and found none. I then tested for nitrite and also found none. I was a bit confused, however I figured that the pre seeding must have established a good colony from the start.

I then tested for nitrate and found a high concentration which reinforced my initial thought. The next day I tested for ammonia again, and without adding any found ammonia in the tank found a relatively high concentration of ammonia back in the tank. There are no fish in the tank, and no other source of ammonia that I can tell.

So I then tested for nitrite and still found none.

So, I figured that the cycle just wasn't done, and began to add ammonia again. Since then, I always find ammonia when testing, but no nitrites.

The test kit is new, and I tested with another kit and got the same results. I've cycled easily 50 tanks at this point, but have never seen this before. The tank is drilled with a homemade sump, and nothing has been changed in the setup.

Is there something that could have wiped out the bacteria colonies that break down ammonia, but not the colonies that break down nitrite? I've continued to add ammonia, but never see a complete breakdown of all the ammonia in the tank (even after several days of not adding ammonia).

Any thoughts would be appreciated.
 
CA-Delta;4382594; said:
If you can't test daily you will have no real idea how effective your method is.
Click to expand...

I have been testing daily since the initial test about a week after the tank was setup. I will occasionally test twice a day (about 12 hours after adding ammonia) to try and determine the speed of breakdown. I am adding pure ammonia, carefully measured to get the ppm up to the desired level based on water volume and current ammonia concentration. This is the same way I have cycled every other tank I've done. I am using non-expired drop kits from API, and tested with a friends Salifert kits to double check, as I initially had doubts about my kit.

After the one test where no ammonia was seen, I am observing ammonia every day regardless of whether I add it or not. There is obvious breakdown of some of the ammonia, but not all of it.

This suggests to me that the cycle completed, but some of the bacteria colonies died off since then. Whats weird is, I can't figure out where the extra ammonia is coming from, and why additionally the nitrite is being broken down while the ammonia is not. I've never seen the nitrite portion of the cycle finish before the ammonia part.

Furthermore, I have have done two partial water changes with treated RO water, and always find steadily increasing levels of nitrate in the water. This also reinforces the fact that some ammonia is being broken down, as well as ALL of the nitrite in the tank.

Anyone else?
 
It is unlikely you are using "pure" ammonia.
You could and should be using ammonia devoid of additives.
Any chance you could post the results of your tests in chronological order ?
Just ammonia and nitrite and whatever you added daily.
It would also be helpful to know what % ammonia you are using.
I'd be willing to bet this will solve itself in short order, AND, I'll bet a number of people interested in fishless cycling will learn from this. :)
 
Any chance you could post the results of your tests

Really need numbers.
What amount are you dosing the ammonia at?
Nitrate level?
Without more info it`s all a guess.
 
Poklei;4386755; said:
JuS put a crapload of goldfish in there then throw in a gulper catdish to finish them off
Click to expand...

thats a horrible suggestion...if you knew how much a gulper would cost...:screwy::grinno:
 
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