Why is my Fishless Cycle taking so long

[NickK]

Please help. This fishless cycle is killing me. The first one took 2 months!!! but I had to nuke it to get rid of some tiny threadlike worms I introduced. So now I have started over with 4 new tanks.

The first 2 tanks registered nitrites after 6/7 days. Wow, that seemed fast. I did start both tanks with a "bacteria in a bottle", and it seemed like it was working. Both tanks had spiked nitrites in less than 2 weeks. Since then, now on day 22, nothing has happened. No nitrates. The ammonia is still being added (very sparsely) and consumed.

How long does it typically take to show Nitrates after the Nitrite spike? I guess it has been 16 days with nitrites in the tank.

Conversely, I have no idea why the other two tanks (started about 18 days ago) still haven't seen the first nitrite. Very weird.


Thanks,
Nick

Nick,
I can't help you with the question on why there are no nitrates yet, but i have an idea for your tanks that still don't have nitrites. Assuming you have two filters on each tank, ie a sponge and a HOB or two sponges or something, take one of the filters from the two tanks that is showing nitrites and add them to the two tanks that aren't showing nitrites yet. Take one filter from each tank that isn't showing nitrites yet and put them in a tank that is showing nitrites. Basically it's a swap so each tank has one filter that IS turning ammonia to nitrite and one that isn't. That should at least get all the tanks on the same level.

Brad

[Ardan]

Hi,
Usually it takes at least 2 to 3 wks for each phase of the cycle. It depends on the bioload (amount of ammonia), temp, ph etc.

A higher temp (80F+) will speed the process.

A higher (not sparse) amount of ammonia speeds the process as it results in higher nitrites to feed the bacteria.

Use ammonia (no sudsy or lemony)to bring the concentration in the aquarium to about 5 ppm.

hth
Ardan

[ronrca]

Sorry Ardan! I will be contridicting you!

The ammonia stage is the quickest stage as the bacteria responsible for consuming ammonia multiply quickly, around 8-12 hours! However, bacteria that is responsible for the nitrites multiply somewhere around 24 hours therefore making the nitrite stage much longer.

It is not uncommon for the ammonia stage to take around a week and the nitrite stage around 2-3 weeks.

My advise is not to add too much ammonia as it is possible to have too many nitrites meaning your nitrites will never come down. With every drop of ammonia being added daily, your nitrite will keep rising higher and higher not allowing the bacteria a chance to 'catch up'! Once you start getting nitrate reading that are off the kit scale, do a 50% water change and then add enough ammonia to max the kit scale. Then first the next day!

[Ardan]

hi,
I was only basing on personal experiences. If I do large wc's and keep the nitrites low, then the cycling takes longer than if I let the nitrites rise to higher levels.

Each phase (length of time) of the cycle depends a lot on temp, ph, etc

You are correct in saying that "Nitrobacter bacteria " (some say its another bacteria) are slower to reproduce (they eat nitrites), than "Nitrosomaonas bacteria" (they eat ammonia). That phase of the cycle can take longer.

Ardan :sun:

[ronrca]

Fair enough! I agree with prolonging the cycle via large water changes. I would only recommend water changes once nitrates are quite high.

you could put out the money for Bio-Spira to get one tank going, and then after a week or so move one sponge to another tank for a week and just keep doing that to get them all going.