Tank not cycling - ideas why?

[asder112]

Hi all -

I'm currently attempting to cycle a 35 gallon tank using the fishless cycling method. I have 2 hob filters on it (forgot their make/model, will check when I get back from work), and it is heated to around 78 degrees farenheit. No air bubblers currently.

So I understand the concept behind cycling, and I have been adding ammonia to the tank regularly. I seeded the tank with the water siphoned from the gravel of my established 55 gallon tank. Initially, I added in waaaaay too much ammonia, but once I realized it I changed the water and brought it back down to around 5 ppm (which is where it is supposed to be, afaik). For about a week the ammonia level would slowly fall and I would top it off with more ammonia, keeping the ammonia level at around 5 ppm. However, these last two weeks the ammonia level suddenly stopped slowly decreasing and has been staying constant, indicating that the bacteria level is not increasing at all. I have tried seeding again (once again siphoning water from the gravel from my established 55). I'm just wondering though, where did I go wrong / what am I doing incorrectly this time? Am I missing something?

Thanks!

 

[pacu mom]

Most of the beneficial bacteria resides in your filter media. Just using water from the old tank introduces very low amounts of bacteria to your new tank. Seeding with media from a cycled tank would work better....even putting some of the gravel from the cycled tank into the new tank would work better than water. There are also biological additives that can be used to jump start the cycling process in the new tank. You just need a better source of beneficial bacteria to seed your tank, than water.

 

[asder112]

I understand that it is a low amount of bacteria that I would be getting. However, don't bacteria grow exponentially, assuming there is enough food to support their growth?

 

[dawnmarie]

Are you using "Clear Ammonia" ? IE : No additives.
Have you tested any water quality parameters other than Ammonia ?

 

[MadRussian79]

Bacteria do grow exponentially give ideal conditions and a lack of bacterial waste products. Check your nitrite and nitrate if either of these are high then that can slow or stop the cycle.

Can you give us some number on how much ammonia you are adding to the tank and how often to maintain the 5ppm.

 

[asder112]

I'm adding clear, unscented ammonium hydroxide (10% concentration). I have been testing nitrite and nitrates, and they spiked for a couple of days. However, they subsequently (nitrites and nitrates) dropped w/o me doing a wc, and ever since they have been at 0 while the ammonia is staying at around 4 ppm. My guess is that I probably messed up the tests somehow, or that it was cycling and then something messed it up. Probably messed the testing up.

In terms of amount of ammonia added - I add around 20 drops per 1 ppm below 5 ppm. Would it be easier if I just tossed in flake food instead of messing around with the ammonia>?

 

[dawnmarie]

That is weird, I've not heard of Nitrates disappearing without help.

By chance is your water supply Chlorinated ? If so did you use a dechlorinator ?

What are the parameters of the source water (tap water, etc.)

edit: Are both HOB filters new?
What else is in the tank besides water ?

 

[iloveoscars702]

if you have a 55 running then run the est filter on the new tank. or run the two hob on the 55 for about a week to grow bb colonies and then put it on the new tank.

 

[asder112]

if you have a 55 running then run the est filter on the new tank. or run the two hob on the 55 for about a week to grow bb colonies and then put it on the new tank.

I would but they wont fit on the back of the 55.


AFAIK, my water supply is not chlorinated (my living bgk should be proof of that) - I get soft, acidic (6.0 pH), well water.

The 2 filters were previously used (a loooong time ago) for a 10 and this 35 gallon tank, before I dismantled them.

I think I'm just gonna reset again. I just hate having wasted 3 weeks.

 

[Toby_H]

Most of the beneficial bacteria resides in your filter media. Just using water from the old tank introduces very low amounts of bacteria to your new tank...

　
I completely agree with Pacu Mom that the vast majority of your bacteria is residing on surfaces and very little is ever suspended int he water column at any given time, thus adding "old tank water" is essentially useless to seed a tank...
　
Filter media is a suitable environment for bacteria to cultivate, but so are many many other surfaces commonly found in a system...
　

However, don't bacteria grow exponentially, assuming there is enough food to support their growth?

　
Yes they do…
　
But start with 25 and increase it exponentially…
　
Now start with 1,000,000 and increase it exponentially the same amount of times…
　
　

I have been testing nitrite and nitrates, and they spiked for a couple of days. However, they subsequently (nitrites and nitrates) dropped w/o me doing a wc

　
This is a sure sign of mistake. If you did nothing to remove the nitrate… and it disappeared… then there is something going on that conflicts with science… You will need to determine where the mistake lies before solving anything further…
　

My guess is that I probably messed up the tests somehow, or that it was cycling and then something messed it up. Probably messed the testing up.

　
I agree… but you’ll need to retest with accuracy to better evaluate where you are, before anyone can advise you how to move forward…
　
　
I suggest you do a nice big water change to remove/reduce your pollutants… but do not “sterilize” the system and kill off any bacteria you may have built up…
　
Then reset your ammonia… then add a nice handful of mature media from your 55 gal into one of the HOBs on the 35 gal…
　
This will ‘properly’ seed your tank giving you the jumpstart you are looking for…
　
I personally see very little reason to dose the tank with 5 ppm of ammonia daily, as it would take a grossly overstocked tank to ever produce this much ammonia. Cycling to 2~3 ppm is plenty…