20 Gallon Tank Fishless cycle (since Oct) stalled, need help to restart.

grepis

Member
Ok, I am doing fishless cycle since mid of October in my 20G tank. I definitely had both colonies of bacteria (at least in past), because I saw as my ammonia went down, and nitrites went up. Then nitrites went down and I see reading of nitrates. But...
1. I never saw that my 2ppm ammonia go down to 0 within 24h. It always took at least 4-5 days.
2. Same situation with nitrite, it took days before it go down to zero.
3. And now, 2 weeks ago my cycle completely stalled. No progress. I did water change (~50%) week ago, but zero progress after that too. My ammonia stuck at 1ppm and nitrites read only 0.25ppm. Water that added to aquarium treated with Tetra Aqua Safe.

Temperature - 80F. ph 7.6-8 (but I have to make recent checks too). TOP FIN HOB filter (filled with seachem matrix). Air stone.

I have no idea what to do. Definitely my cycle was sluggish before (first nitrites readings appeared at mid of november, so my expectation would be that by the end of december they should be easy to process 2ppm in 24h).
 

MakenaSunny2020

Member
Looks like you got a solid tank. My cycle in my tank got messed up before and I had to restart it. Have you considered using any products such as turbo start, that can sometimes correct it.
 

mattgirl

Member
Welcome to Fishlore

I will try to help but I will be asking questions along the way. I need more information to be able to get to the bottom of what is going on.

What is your ammonia source? When you saw it drop to zero each time did you add more? A cycle needs a constant supply of ammonia.
 
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grepis

Member
Thank you for attempting to help.
mattgirl said:
What is your ammonia source?
Dr. Tims. pure ammonia
mattgirl said:
When you saw it drop to zero each time did you add more?
Yes, I added ammonia each time when it is drop to zero (and at the beginning of cycle, each time when was close to zero). So it always was some ammonia in tank.
I measured pH ~8, kH = 50.
 

mattgirl

Member
grepis said:
Thank you for attempting to help.

Dr. Tims. pure ammonia

Yes, I added ammonia each time when it is drop to zero (and at the beginning of cycle, each time when was close to zero). So it always was some ammonia in tank.
I measured pH ~8, kH = 50.
Was the 50% water change you did the first one you've done on this tank? If so it is possible the water was what I call dead water. It is simply water that has had all the minerals used up.

Either way, I would change out no less than 80% of the water today. Doing so should get the ammonia down close to zero. If so add enough to get it up to no more than 1ppm.

I am also going to suggest something that may sound strange but it does help. If you don't have any I will recommend you get some fish flakes. Brand isn't important. Crumble up a small pinch of it and put it in this tank daily along with the liquid ammonia you are using.

This thread will explain my thoughts on adding fish food while fishless cycling.
 
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grepis

Member
It was second time when I did 50% water change, plus small top ups of evaporated. I am going to do massive water change today then.
 

mattgirl

Member
grepis said:
It was second time when I did 50% water change, plus small top ups of evaporated. I am going to do massive water change today then.
Please keep me updated and I will try to help you until we get this tank back on track.
 
  • Thread Starter

grepis

Member
So far 80% PWC, top up ammonia to 1ppm, added some fish food flakes. 24h no changes in ammonia.
 

mattgirl

Member
grepis said:
So far 80% PWC, top up ammonia to 1ppm, added some fish food flakes. 24h no changes in ammonia.
I wouldn't get too concerned for at least a week of adding a pinch of fish food daily. I can't swear this will get things moving but have high hopes that it will. Do you have any media other than the matrix in your filter? If not I would add a sponge of some kind.
 
  • Thread Starter

grepis

Member
mattgirl said:
Do you have any media other than the matrix in your filter? If not I would add a sponge of some kind.
I added sponge filter as a standalone yesterday too. HOB is TopFin - not much space for anything.
 

mattgirl

Member
grepis said:
I added sponge filter as a standalone yesterday too. HOB is TopFin - not much space for anything.
Good job. The sponge filter will add a great place for bacteria to grow. Bacteria grows on everything in our tanks but the majority of it is going to be on our filter media since that is where the most food is going to be.
 
  • Thread Starter

grepis

Member
It is not update, but just to let know that 1.5weeks ago plans drastically changed and some of the tetras send to this aquarium. I did 100% water change to get rid of any ammonia, treated water and filled up tank. So far I did only one 30% water change. I had one ammonia spike ~0.25, treated it with Prime and 2 days later it went down to 0 and no nitrites detected so far. I am doing daily ammonia/nitrite tests and daily feeding. I will tests for nitrates on weekend.
 

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