Stuck With Cycle

[OneEyedJack]

Hey all,
 
new to the forum but long time lurker taking in bits of advice as I go. However I am now stuck during a cycle and need some help.
 
I have a 60l tank which has been cycling for around 11 weeks and all was going well until recently. I'm doing a fishless cycle and using pure Ammonia as the source. As I say, all was going well, I was dosing the tank to around 4.0 and after a while it dropped. I dosed it back up and waited until it dropped again. Eventually it did and the tank was showing high Nitrite readings of around 5.0 (was turning purple as soon as the drops hit the water). Continued testing and eventually Nitrite dropped to 0. At this point I tested for Nitrate and the reading was high (somewhere between 40 to 80). I read that the cycle has finished once Ammonia can reduce with around 12 hours so I dosed back up to around 3.0 but the Ammonia never dropped after testing for around a week.
 
The reading was still sitting at 3.0, Nitrites were at 0 and Nitrates were high. Ammonia wouldn't come down. Eventually I did a water change which reduced Ammonia to about 1.0 but again this never ever disappeared. I dosed the tank back up to 4.0 to keep the cycle going but after around 4 days this has not come down at all. Nitrites are sitting at 0 and Nitrate is at 10 following the water change. 
 
Have I stalled the cycle by doing the water change or can there be something else causing the problem? Tap water PH is around 7.2 and Tank Water is sitting around 6.8.
 
Any help is greatly appreciated as it's driving me mad  

 

[the_lock_man]

Add some bicarbonate of soda, bit by bit, until your tank water pH is around 8.0. Crashes like this often occur at this point, because all the nitrates turn into into nitric acid, causing the pH to drop. The bacteria like growing at high pH.
 
Also, keep your dosage down to around 3ppm - the latest thinking is that this is optimal, and we are re-writing our advice topics at the moment to reflect this.

 

[OneEyedJack]

Thanks Lock Man appreciate the help! Was starting to panic in case I'd done something wrong. I've added the bicarbonate of soda and have raised the ph to 8 so I guess it's back to the waiting game and hoping things kick in again. I'll be sure to dose ammonia to 3.0 from now on also.

Just out of interest do you have any idea of how close I am to the end of the cycle?

Thanks again.

 

[OneEyedJack]

Wanted to follow up on this thread in case anyone ever finds themselves in a similar situation and wonders how this panned out, could also use some follow up advice. 
 
So about 4 or 5 days after adding the bicarbonate of soda the levels of ammonia started to drop again. Nitrite was reading 0 and I dosed the tank back up to 3ppm of ammonia. This dropped
back to 0 Ammonia and 0 Nitrite after 24 hours. Nitrates were back at high levels (around 30 - 40). Dosed back up to 3ppm of ammonia and this time the ammonia wasn't quite back to 0 after 
24 hours. 12 hours later, it was finally at 0.
 
Over the past few days the tank has been turning 3ppm of ammonia into nitrites in around 24 hours but nitrites are showing as dark purple. Within around 12 hours these will return to 0. So basically
its taking around 36 hours to leave 0 ammonia and 0 nitrite. PH is still sitting around 8 and Nitrates are still really high (dark red).
 
So everything seems to have kicked back in again but I'm guessing that the tank has not fully cycled as it's taking 36 hours to turn ammonia into nitrates. Will this eventually reduce down to the 12
hours expected or should I be doing anything else?
 
Any other help would be great, this has been cycling for about 13-14 weeks now! 

 

[snazy]

The period of time it takes for these to be converted should reduce.
However, if you are just going to stock the tank slowly, not full stock at once, then you maybe good to go now.

 

[daizeUK]

I would keep going until your nitrites reach zero within 12 hours and ideally doing that consistently for a week before you stock.

 

[OneEyedJack]

Hey guys, thanks for the advice. I have a plec in my existing tank which I've had for a while and grown pretty fond of so don't want to risk putting him into the new tank if it's going to be harmful so may hang off until the reduction is happening within the 12 hours. Any idea how long it's likely to take for this to come down? I know that may be a bit of a million dollar question.
 
Issue is tho, the arc tank causes water to evaporate quickly and level is constantly going down. Not sure about topping it up as I've read mixed views on whether topping up water can slow down a cycle or not and slowing it down is the last thing I need

 

[daizeUK]

Topping up evaporated water will not slow a cycle down.  It sounds like the cycle is pretty close to finishing, should not take too long now.  I'd guess roughly about a week give or take, impossible to tell though.
 
Just curious, did you not use mature media from your existing tank to kickstart your cycle?

 

[OneEyedJack]

Yeah I did, I removed the bio media from the filter and replaced it with a second sponge from my existing tank. I was doing the add food method. This made a complete mess of the tank and didn't smell great. On top of this I was seeing no movement in ammonia numbers so I drained the tank and started again. That's when I got some ammonia and started adding that instead. I'm guessing that the draining of the tank and starting again killed off any beneficial bacteria that was in media in the first place.

 

[daizeUK]

It wouldn't unless the sponge completely dried out.  It might be more likely that the fish food produced too much ammonia and that might have killed off the bacteria; they don't like concentrations of more than 5ppm.