Fish-In Cycling Question

[Ktownmatt]

Hi,
As an introduction, i had a couple of freshwater aquariums for a decade or so, and am back after a few years off... I used to have an account on this site, but for the life of me can't remember the username or which email address i used.

Anyway, 2 weeks ago i bought a 37G tank and am cycling it with a dozen Golden Danios. It has a handful of Java Ferns and Crypts, with a Fluval Stratum substrate.
I've been testing my ammonia and nitrites daily, and am consistently reading .25ppm Ammonia, and 0 Nitrite. I checked the guide, and am using the API Master Test kit properly.

I don't remember it taking this long to start creating Nitrities last time - is it normal? I've done a few 50% water changes, but am hesitant if i'm not giving the ammonia a chance to start the cycle. Perhaps the plants are absorbing the ammonia and slowing down the cycle? I don't want to add more cycling fish to create a larger bioload if that's not the issue.

Any ideas?

Thanks in advance...

 

[BBradbury]

Fish In Tank Cycling

Hi,
As an introduction, i had a couple of freshwater aquariums for a decade or so, and am back after a few years off... I used to have an account on this site, but for the life of me can't remember the username or which email address i used.

Anyway, 2 weeks ago i bought a 37G tank and am cycling it with a dozen Golden Danios. It has a handful of Java Ferns and Crypts, with a Fluval Stratum substrate.
I've been testing my ammonia and nitrites daily, and am consistently reading .25ppm Ammonia, and 0 Nitrite. I checked the guide, and am using the API Master Test kit properly.

I don't remember it taking this long to start creating Nitrities last time - is it normal? I've done a few 50% water changes, but am hesitant if i'm not giving the ammonia a chance to start the cycle. Perhaps the plants are absorbing the ammonia and slowing down the cycle? I don't want to add more cycling fish to create a larger bioload if that's not the issue.

Any ideas?

Thanks in advance...

Hello K...

You're removing too much water, pure and simple. You're removing the nitrogen the bacteria needs to reproduce. When you have a positive test for either ammonia or nitrite, remove 25 percent of the water and no more. This amount will keep the fish reasonably happy and still feed the bacteria. Danios are a fairly hardy species and should tolerate the higher nitrogen. Feed the fish just a little every day or two to maintain a steady source of ammonia. A dozen small fish really isn't enough for a mid-size tank. I recall using 6 to 8 Guppies for every 10 gallons of water I wanted to cycle. Just test the water daily and remove one-quarter if you have a positive test for ammonia and nitrite. When you get several daily tests with no traces of these forms of nitrogen, the tank is cycled. Then, you simply remove and replace half the water and service the filtration system every week for the life of the tank.

B

 

[Ktownmatt]

Thanks. I suspected that i wasn't giving the bioload a chance to grow/evolve. When i cycled my first tank, it was the same fish in a 20G.

 

[King Fisher]

How long has it been since you started?

 

[Ktownmatt]

2 weeks. it's longer than i remember to start building ammonia, but my memory isn't too trustworthy these days.

 

[King Fisher]

With a fish in cycle you should be at .25 ppm ammonia so if that's where you are at consistently then that's a good thing. Realistically you have another 4 weeks to go so I'd just be patient with it and let it come along.