Tank Not Cycling

[RedSandman]

Hi,
 
I started doing a fish-less cycle with a 36L tank. But after 3 weeks I decided to replace the internal filter for a 'hang-on-the-back' filter. I won't go into the details of why here. Therefore, I restarted the cycle and re-dosed with Ammonia. I checked the Ammonia, Nitrite and Nitrate and pH  levels after 5 days and to my surprise I had zero Nitrate, zero Nitrite and Ammonia 4.9 ppm, pH 7.6.
 
Using  the Nutrafin Test Kits the Ammoina colour intervals are:   0,  0.6,  1.2,  2.4,  4.9,  7.3.
 
I am a bit puzzled as this means the tank is not cycling (i.e. the Ammonia dose is not being converted).
 
Other notes:
 
1) All the water was treated with water conditioning when the tank was filled.
2) The initial fishless cycle seemed to be working with Nitrate Nitrite readings increasing with steadily reducing ammonia levels.
 
If anyone could offer an opinion as to why the tank isn't being cycled it would be appreciated.
 
 
 
 

 

[Fishmanic]

unless you took media from your old filter and put it in the new filter,  the cycle is basically starting all over---it may take more time to start seeing nitrites--you also should do a 1/3 water change to bring your ammonia level closer to 3 ppm as recommended in the fishless cycling procedure posted on this site---patience will be rewarded

 

[RedSandman]

 
... you also should do a 1/3 water change to bring your ammonia level closer to 3 ppm as recommended in the fishless cycling procedure posted on this site ...

 
Ok I understand the ammonia level is higher than the recommended. But notwithstanding the errors in the test kit I would not have thought that 4.9 ppm compared to 3 ppm would have made much difference. Surely, I higher level of ammonia would mean the bacteria have more food available to grow and therefore reproduce.

 

[Ch4rlie]

Too much ammonia can have negative effects. Can slow down your cycling at best. In fact if ammonia is too high, bacteria can die.
 
This happened in my friend's tank when he accidentally put in far too much ammonia, left it there for a day or so, no bacteria at all left over, had to start cycle over again.
 
3ppm of ammonia is actually quite a lot, in most tanks, fish will not actually produce anywhere near 3ppm.
3pm is actually a bit overkill but this will produce plenty of bacteria and when your stocking is added, the bacteria will easily consume whatever amount of ammonia the stocking will produce, probably nearer 1ppm if anything, and the rest of the bacteria will either go dormant or die off leaving you with the right amount of bacteria for your tank stocking, this is also why it is recommended you fully stock your tank as quickly as possible after completing fish less cycles.
 
Hence why the limit was decreased from 5ppm to 3ppm in TTA's Cycle a Tank.

 

[RedSandman]

Ok thanks Ch4rlie, I will do an immediate partial water change to reduce the ammonia level.
 
The ammonia level is now nearer the next colour interval down (i.e. 2.4 ppm).
 
I will test every few days to see how it goes.

 

[daizeUK]

If your cycle is starting from scratch then I'm not surprised.  It can take 2-3 weeks before ammonia starts to process in a new setup.

 

[RedSandman]

 
If your cycle is starting from scratch then I'm not surprised.  It can take 2-3 weeks before ammonia starts to process in a new setup.

 
Well it wasn't completely starting from scratch. It was a new filter but I had assumed there would have been a bacteria culture load on the gravel and tank decorations, perhaps not significant but enough to kick start the cycle.

 

[Ch4rlie]

Substrate and tank decor do not have much bacteria at all really.

The main bacteria colony should be in your filter. Did you move filter media from previous filter to your new HOB filter?
You don't actually say if you did this or not. Am assuming you did not since you cycle seems to have stalled a bit.

Let's hope there is a little bacteria on your substrate and decor to start the ball rolling again.

Will take a little while to get you bacteria to establish in your new filter and grow to strength.

 

[RedSandman]

 
Did you move filter media from previous filter to your new HOB filter?

 
No, the internal filter went into a new tank my daughter brought. So I suppose in reality it is a brand new cycle.

 

[RedSandman]

Did another test today, Ammonia level the same ~2.4 ppm, no nitrites and no nitrates.

 

[Ch4rlie]

Give it time, you will eventually get some bacteria growing, once it starts to be a decent seized colony, you'll start to see nitrites then nitrates although don't worry about nitrates really.
 
Patience is a virtue they say..............I was the same when I first started, could not wait but still does not help time go any any quicker! 

 

[RedSandman]

I did a small 10% water change yesterday, just to dilute the ammonia levels. Today, I did a nitrite test and there was a faint trace of nitrite.
 
So it looks like the cycle is just starting.
 
Two lessons learnt here 1) Don't overdose with ammonia, it inhibits the bacteria growth and 2) have patience.

 

[Ch4rlie]

Two lessons learnt here 1) Don't overdose with ammonia, it inhibits the bacteria growth and 2) have patience.

 

Could not have put it any more perfectly than that!