Fishless Cycle Help!

[kimGeach]

Hi

Five weeks into a cycle - ammonia has been clearing within 12 hours after the second week - the nitrite is presently taking 16hrs (ish) but making progress slowly in the right direction.

Tested the ammonia last night and it was still high (a slight drop from 5ppm) and has not dropped much when tested this morning (so over 24hrs now)

Any idea what's gone wrong?

Tanks been running slightly hot at 80 degree's as i understood this would assist with bacteria growth.

we cut down adding ammonia to once a day 2 weeks ago when the ammonia had converted within 12 hrs. started doing water changes as advised to help with the amount of nitrite being dealt with (roughly 10 - 20 %) once a week. We have nitrates (top of scale)


The tanks a trigon 190 (190 litres)

any suggestions gratefully received - please!

 

[waterdrop]

Well, given that nitrates are at the top of the scale and given the stage you are at, it could possibly be a pH crash. In the Add&Wait method we tend to discuss a lot here, we usually recommend testing for pH right along with ammonia and nitrite(NO2) most of the time. The bacteria grow optimally in a pH of 8.0 to 8.4 and the process slows down as your pH goes down through the 7's and stalls if it gets down to 6.2. The fishless cycling process itself, particularly via the acid nitrates(NO3) that build up will drive the pH down sharply once your buffer (KH measures this) runs out in the tank. The solution usually is that you may have needed --more than one-- very large water change to get rid of nitrates and then recharge with ammonia and let it get going again.

(some of this is just a guess of course going on your description rather than the hundreds of entries of data from your log that would really tell the story!)

~~waterdrop~~

 

[Miss Wiggle]

agree with above, pH is the usual suspect

did yopu keep a log of all your readings? if you could post that up it would help us out

 

[Colin_T]

Try doing a 50% water change and then see if that helps.
Having warmer water does help speed up the growth of the bacteria. However, if there isn't enough oxygen in the water it will slow the growth. Likewise if there is too much ammonia or nitrite it will slow things down.
Increase aeration/ surface turbulence to maximise the oxygen levels in the tank.
Don’t worry about testing for nitrates just yet as nitrate test kits will read nitrite as nitrate and give you a false reading.

 

[kimGeach]

Hi

Thanks - No not been keeping a log will start now.

There's been a airiater (or how however you spell it) running all the time. will have a look at PH and sort a water change

Thanks guys