Cycling question

[Sinuhe]

I was just wondering how can I tell where the cycle is going if I have no detecable levels of ammonia, nitrites or nitrates? I set the tank up a week ago (a 33 g/ 128 l), it's got live plants, 2 Zebra Danios, and a fairly powerful HOB filter. At no point during this week while testing have I found any ammonia (the chart for the liquid test starts from 0.5ppm), and when I did a full range of tests today, there are no nitrites or nitrates, either. The pH has remained the same (8,0), the general and carbonate hardness have gone up one notch (5dH and 4 dH, accordingly). (I've also added a bit of salt). As far as I can tell, the fish are doing fine, and the water looks clear. The temperature is about 24C/ 75F. I'd imagine the cycle is going to take at least one more week. Should there be a detectable level of ammonia at some point during the cycle, or can the ammonia spike slip by unnoticed?

 

[LondonGman]

The best article that one of the advisors here points everyone to read is

http://faq.thekrib.com/begin-cycling.html

it will explain it all

EDIT I could answer your question but it would be based on information I got from that webpage so…..

2nd EDIT Curious, how much water are you changing and how often

 

[Sinuhe]

Thanks for the link, I've been to that site before.

I haven't done any water changes so far, but am going to change about 1/3 today (I want to vacuum the gravel, and dilute the bit of salt I added when I thought the fish might have been sick with something, but I'm not sure if they ever were, and seem fine now).

 

[LondonGman]

Should there be a detectable level of ammonia at some point during the cycle, or can the ammonia spike slip by unnoticed?

Not sure on this as I did not do daily water checks when i started but I took weekly samples to the shop and they too never noticed any ammonia in my tank.

In your tank, your fish’s uneaten food, “poo” and any other waste organic material, naturally decompose creating ammonia. In time, bacteria converge to feast on the ammonia and continue to do so as long as there is ammonia. The amount of bacteria in the tank will match the amount of ammonia the tank produces, bearing in mind the oxygen and surface area the bacteria has.

If you have not noticed any ammonia, bearing in mind you have only 2 danios in a 33 g tank then either

• - None has been produced (unlikely but not impossible) or
  - too little to detect
  - faulty test (??) or
  - Your bacteria are already working

 

[jsoong]

When I cycled my 10 gal, the NH3 went to trace at about day 4 & then nothing thereafter. I too have plants in the tank, maybe they are taking up the NH3 faster than the bacteria?

The NO2, however, was another story. I had NO2 spikes for some 2-3 weeks before it all of a sudden crashed.

If the bacteria are transforming the NH3, you should be seeing NO2. The NO2 bugs are much slower in establishing themselves, and I would be suprised if the NO2 spike is missed.

As noted by LondonGman, you do not have a large bioload in your tank. Maybe the plants are eating up the NH3 before it gets to the bacteria, in which case there would not be even the beginning of a cycle yet.

 

[Madame_X]

If you have not noticed any ammonia, bearing in mind you have only 2 danios in a 33 g tank then either

• - None has been produced (unlikely but not impossible) or
  - too little to detect
  - faulty test (??) or
  - Your bacteria are already working

Or the plants are consuming the ammonia.

What kind of plants do you have in the tank? If you have any kind of fast-growing stem plant, that's probably what is happening. Two fish don't generate that much of a bio-load.

I have a 30 gallon planted tank with only three fish in it, and it has been up and running for about 6-7 weeks now. I have never had any measurable ammonia, nitrites or nitrates in this tank. The plants consume everything.

The plants will make the cycle take longer to complete, but its healthier for your fish. You will have to slowly increase your fishload to get the tank to cycle, though. I don't think it will ever cycle with just two fish when there are plants in the tank.

 

[Sinuhe]

Hmm, I guess that's both good and bad . For the first few days, I only had some java ferns. Then on the 5th day or so I added some new ones (forgot the name), and again today I added a third kind of plant (don't know the name, but asked for its requirements from the store keeper, who says it's fast-growing). Now there are quite a bit of plants in the tank, which will probably slow down the cycle quite a bit. I wouldn't mind getting more danios to jump start the cycling, but I also had the 2 danios already breed, and now have a bunch of tiny fry that will probably die since I can't provide them with proper care right now. If some of them do survive, they should be adding to the bio load in a few weeks .

 

[Madame_X]

Wow! At least you know your fish are happy and healthy. They must really like their new tank.

I'd wait a couple of weeks at least and see if any of the fry survive. If not, add a couple more fish and do your testing daily (or every couple of days at least). If you still don't see any ammonia a couple of weeks after that, add a couple more.

Here is a good article about cycling a tank with plants. I found this very helpful.

http://www.csd.net/~cgadd/aqua/art_plant_newtank.htm

 

[Sinuhe]

Thanks! Wow, I never realised you should consider something like that when starting out with a planted tank. All the tutorials I've read about starting an aquarium basically say: add gravel, add filter and heater, add plants, add fish => cycle. But I consider slow cycling a lesser problem than having sky high ammonia all of a sudden. None of the fry will probably survive, but I'll keep an eye on possible survivors. I'm a bit iffy to add more store-bought fish without QT'ing them first .