very strange...need advice

[goldylox]

I have had my tank now for about 4 months and I am/was cycling it with fish in it. The weird thing is, I don't think it is cycled yet. Everything I have read here from posts and articles says it takes about a month for the tank to cycle. My levels are:
pH = 7.6
Ammonia = 2.4
Nitrite = 0
Nitrate = 0

Why is this happening? I have been doing teeny tiny water changes (about 10%) about once every two weeks. I have not vaccuumed the gravel as per the instructions of those here. Any ideas why my tank won't cycle?

Thanks in advance!

goldylox

 

[Jchillin]

The fact that you have high NH3 and no NO3 means that the tank hasn't cycled yet. What type of filter are you using and what was the time period between adding fish and removing them?

 

[penpitt]

Are you cleaning your filter and if so are you rinsing the media in spent tank water so you're not killing off the bacteria. With the light stocking level in your 55 I would'nt see the need to clean your filter but once every 3+ weeks.

 

[Menagerie]

55 gallon
4 popsicle tetras
2 pearl gouramis

That is a very small bio load to cycle the tank.

 

[number2of7]

That is a very small bio load to cycle the tank.

I agree!! Good excuse to go buy more fish! I vote for some zebra danios...they are a hoot to watch!

p.s. Go Thrashers!!!!

 

[goldylox]

I have a penguin biowheel 330 hob filter. I have not been cleaning the filter at all. I added the fish after about two days of having my tank because I was unaware I had to cycle the tank. They have been there ever since and are doing fine!

Zebra danios? I will definitely look into! I have wanted to get more fish for the longest time but I though because the tank was cycling I would leave it.

Thanks everyone!

 

[jsoong]

Agree that the bioload is low, but the NH3 is 2.4. Shouldn't that be enough to start the cycle?

 

[Jchillin]

The NH3 has to get up to about 5ppm to feed and maintain the nitrifying bacteria. With the load being so small, you can't get to that level.

 

[Menagerie]

I have not been cleaning the filter at all.

That's good, since there will not be anything to clean right now.
goldylox, is there anyone around that has an established tank that you could get some filter goo (the good bacteria) from? This would instanly cycle the tank and allow you to add more fish right away.

 

[TomK2]

Jchillin wrote:

The NH3 has to get up to about 5ppm to feed and maintain the nitrifying bacteria. With the load being so small, you can't get to that level.

Can you tell me where you got this from? I am also using a low biload, and was wondering if there was a threshold effect to the cycle.

 

[Jchillin]

TomK - I read a number of articles on cycling and 5 was always the "magic" number. Here's a thread that recently referenced it.

http://www.aquariumadvice.com/viewtopic.php?t=40570

 

[FancyGuppyGuy]

I dont know about wether it has to get to 5 ppm to maintian the bacteria, but perhaps it does require that an ammonia spike happen for the bacteria that convert ammonia to bloom. I do know that with such a small number of fish in a large tank it will tank along time to cycle completely. eventually you will cycle its just going to take alot longer.

I do wonder why there is no Nitrate though would seem after 4 months of never cleaning anything you would get some Nitrate.

When was the last time you added fish?? a few weeks ago?? how many fish did you start with??

 

[TomK2]

GuppyGuy

but perhaps it does require that an ammonia spike happen for the bacteria that convert ammonia to bloom.

That is the million dollar question! Is There is a dose-response curve for the bacteria, meaning that reactivation and growth is different for different ammonia levels? How a varying bioload or ammonia level effects this is information not readily available for the aquarium application. Here is a link that FancyGuppyGuy had on another thread, that implies that the optimal ammonia level for nitrosomas growth is 200 ppm! (Thanks for all the great and informative links Guppyguy, keep them coming!).

http://article.dphnet.com/cat-01/naturewonders3.shtml

But what is the optimum for someone starting an aquarium? I don't know of it being scientifically studied. If you know of any sources that have done this, PLEASE let me know.

Do you think that 5ppm for fishless cycling became the rule simply because that is the way someone did it with success, and it kind of becomes the standard as people duplicate the conditions? Why am I so interested? well, I am wondering if there is a fish bioload threshold below wich cycling takes way, way too long, and a cieling above wich the spikes get way too high. I would love to know if there is a window that produces a resonable cycle time without hurting the fish. My instincts tell me there should be, but I can't find any documentation of this.

 

[Jchillin]

Tom - Believe me I understand what you mean.

When I started my tank, I was cycling with fish (ignorance, I didn't know that was what I was doing). I had a really nice bio-load (didn't know what that was either) but I was informed that NH3 above 2ppm was toxic to the fish. I did a test one day, saw the 2, at the same time, NO2 was at 5, I panicked and tore the tank down. I had no idea that was the cycle really grabbing hold.

Every article (here, elsewhere) describing the nitrogen cycle explains the process (you have NH3, bacteria turns it into NO2 then NO3). I attributed it to the fact that no one knows how much bacteria you are starting with. Since the bacteria enters your tank naturally, it's hard to measure just how much. HTH

 

[jsoong]

TomK - I read a number of articles on cycling and 5 was always the "magic" number.

5 is the magic number for fishless cycling. That is supposed to be a high enough level to give you rapid bacteria growth, yet not so high that the high NH3 actually kills the bacteria & stalls the cycle. <I have not actually read of any study, this is the number widely quoted ... but I don't know the original source where that comes from.>

For fishie cycling, however, the recommended max. NH3 is much lower. For pH of 7.5, the KRIB FAQ recommend keeping NH3 below 1.5. At anyrate, I think a lot of the old time fishie cycler have sucessfully cycled at low NH3 levels <some using fairly sensitive fish>. So I think a tank should cycle at NH3 level of 2.4 .....

I have cycled my QT with NH3 spike at trace & NO2 at 0.3 - but I cheated & seeded with my main tank, so that may not be a good example.

Edit - after reading the link on dormancy, that QT is definitely not a good example. I guess if there is active bacteria, it is possible to cycle using low levels of NH3, but when all you have is dormant "spores", you'll need some sort of spike to activate it. This might be the reason why there is so much variation with cycling. If you are lucky & got some active bacteria to start, then it is much easier. <BTW - I read an old aquarium book that suggests getting a handful of clean garden dirt to seed a new setup - that may be a source of active bacteria?>

 

[Jchillin]

Jsoong - This is one of the articles where I "learned" about the nitrogen cycle factors and "where did the bacteria come from?" question. There is still no way of measuring when, what, where due to not knowing how much "dormant" bacteria already exists plus, how much bacteria enters after.

The article states clearly that the only way to do this is under controlled conditions in a lab. Hence, most tanks "cycle" in about 4-6 weeks. What most aquarists want to do is "instant cycle" which is why bio-spira is so popular. Seeding with cultivated elements from cycled tanks (as you state) is also popular. I would think that a tank containing 200ppm would have a distinct odor and gosh, how do you bring that down to normal with the foul smell to boot.

 

[FancyGuppyGuy]

Perhaps the low ammonia isnt always 2.4?? or has it just now reached this lvl?? The Bacteria needs a constant and stable supply to be activated. Maybe over the last 4 months its been to low and with those small changes just enough variance for the bacteria to decide its not time yet to bloom. I would think that sooner or later it will decide to activate possibly at 3 ppm?? I have no idea because Ive cycled with at least 5-8ppm ppm at its highest point.

Anyhow sooner or later it will cycle its just going to take longer with such a small bio load.

this thread seems like dejavu BTW lol!! I swear I posted here once already.

 

[goldylox]

Wow, now I am really confused!

Okay, I added my fish about a week after I got my tank which was about 4 months ago. I haven't added any fish since.
The ammonia has been 2.4 for as long as I have been testing (about 3.5 months).
I have some plants (plastic) and some stones from a tank that I used to have and these decorations have not been cleaned since I took down the tank. Would they still have bacteria on them to start the cycle of my new tank?

Thanks for your advice everyone. It is really interesting to read about this stuff when I knew nothing about it before.

 

[Jchillin]

Don't confused goldylox - In trying to discover why your tank hasn't cycled in 4 months, we sorta got sidetracked with what would be the perfect NH3 level to "activate" the dormant bacteria.

The stored stuff would definitely have some dormant bacteria on them. By all means use them. In the meantime, I believe the general consensus is that you may need a larger bio load. I believe some suggestions were made earlier in the thread for this.

HTH and good luck!

 

[Menagerie]

The ammonia has been 2.4 for as long as I have been testing (about 3.5 months).

I think you need a new test kit. At the very least, bring in a water sample to a LFS and have them test it. Ask for the exact values.