A Fishless Cycle Log Of Sorts

[Katch]

So I'm in the process of setting up a 24G DD Nano Cube. I spend a fair amount of time away from the house so I can't be too OCD about testing and adding ammonia etc so this will be a log covering an 'add and wait' cycle with gaps and pauses when I am unable to get to the tank.

I've seen a lot of posts from people in the middle of a cycle panicing because the have to go away for 3 days or so and wondering if it will harm the cycle. From my rudimentary knowledge of biochemistry it is my hypothesis that it shouldn't matter at all.

Profile:

24G Nano Cube - gravel substrate & couple of small plants.
Filter - 750g Fluval pre-filter, lots of sponge, 1100g Biomax, Bioballs.
Lights on for 4 hours a day. 27degrees C

Day 1 - NH3 less than .5ppm - pH 6.5 - NO2 0 (Filling day - left to settle for 24 hours)

Day 2 - NH3 a good 5ppm - (4ml 9.5% Ammonia added - no other tests performed - temp at 26 degrees. away for a few days now I will test for Ammonia when I get back)

Day 4 - NH3 still 5ppm / NO2 - 0 / NO3 12.5ppm / pH up to 7

Day 7 - NH3 5ppm - added a tsp of bicarb to lift the pH to 8ish

Day 10 - NH3 5ppm - NO2 - 0 - NH3 test looked a little lighter possibly...

Day 11 - NH3 4 / NO2 1 - we have nitrites!

Day 13 - NH3 ~0 / NO2 ~1.5 / NO3 lots! / pH down to 7.5 (1/2 tsp bicarb & 4ml of Ammonia added - NH3 3ppm / pH 8)

Day 14 - NH3 0 / NO2 lots / NO3 lots - 4ml NH3 added / pH up to ~9 so 50% w/c then 1.5ml NH3 to ~3ppm / pH ~8

Day 18 - NH3 1 / NO2 lots / NO3 lots / pH 5 - 60% w/c - 2ml Ammonia, 4 tsp bicarb - NH3 ~2 /NO2 1.5 / NO3 lots / pH ~8

Day 20 - NH3 0 / NO2 ~0 / NO3 lots / pH 8 - 4ml added (NH3 0 / NO2 .25@ 12)

Day 28 - NH3 0 / NO2 ~2 / NO3 ~70/ pH 7.4 - 2ml added

Day 30 - NH3 0 / NO2 ~0.5 / NO3 ~70/ pH 7.2 - 2ml added & 8 tsp bicarb

Day 31 - NH3 0 / NO2 0 / NO3 ~80/ pH 8 - Zeros @ 12h - 2ml added @ 24h

 

[OldMan47]

The chemical part of the biochemistry is quite correct Kstch. The chemicals will remain present unless they are removed by biological action. Unfortunately, once the cycle starts making good progress, the ammonia that we add is often removed in less than 12 hours which means 3 days of no ammonia present for those bacteria that need it, using your example. A die back of about 10% per day is the typical estimate for bacteria not receiving any ammonia.
An approach that may work for you, once you reach that stage, is to use the decaying organic material approach instead of continuing with pure ammonia. In that approach you place some prawns, shrimp, in a bag and let them simply rot in the tank. The decay releases ammonia which will keep the cycle going for a few days or even a week. Unfortunately, it will make the whole fish room smell bad which is one reason we favor the pure ammonia approach. You use a fine mesh bag so that you can remove the decayed prawn effectively when you are done.

 

[LondonguyJ]

Interesting...

I have a friend who wants to get into the hobby but is apprehensive as he often spends his weekends in the midlands so this log and it's laid back approach will be interesting to watch. Personally I think your A bacs will fair better than your N bacs when you take time out but again, it'll be interesting to see how this develops.

 

[waterdrop]

Interesting...

I have a friend who wants to get into the hobby but is apprehensive as he often spends his weekends in the midlands so this log and it's laid back approach will be interesting to watch. Personally I think your A bacs will fair better than your N bacs when you take time out but again, it'll be interesting to see how this develops.

I've noticed you've been a good observer of some of the more scientific aspects we attempt to work in to cycling and other freshwater skills. Its always nice to have others interested in this side of things although we all end up admitting its very limited. One of the frustrating things is that there are so very many variable and many never get controlled for, so we can rarely feel we've really moved forward in a scientific sense but just sometimes in the sense of a hunch.

I agree with OM that when we have colonies still submerged and receiving good flow and therefor oxygen, but we provide no ammonia, we get some sort of curve of loss of bacteria and for lack of more detailed descriptions we mention 10%. One thing I've noticed though is that the recovery from these sort of lack of ammonia feeding episodes has always in my experience seemed to be pretty good. People seem to report coming back from them better than one might think. Anyway I'll be interested too.

WD

 

[Katch]

Day 10 no real drop of Ammonia yet.

 

[waterdrop]

That's normal, sometimes it takes two weeks or even three in rare cases for the first drop in ammonia. Once it drops it usually then beings dropping it quite quickly from then on. And somewhere around that time we usually begin to see nitrite(NO2) appearing in the result logs.

~~waterdrop~~

 

[Katch]

Nitrate test turned into ribena today! (Ribena is a blackcurrant flavour drink here in the UK)

 

[waterdrop]

thanks, I wouldn't have known what the heck ribena was, lol

 

[Katch]

So just to clarify - I now need to keep an eye on my Ammonia till the test drops back to near 0 and then raise it up to 3-4ppm again until my Nitrite level returns to 0...

Then, water change and fish.

 

[waterdrop]

Yes, that's the very compact one sentence description, you've got it!

Those of us that watch cases generally define three phases (so we can drop you in a simple mental slot when we see your diary on a given day, lol.)

Phase1 - Before Nitrite Spike
Phase2 - Nitrite Spike
Phase3 - Post Nitrite Spike
Qualifying Week - Verifying a working biofilter

During the Nitrite Spike phase the nitrite readings have reached the maximum capability of the given test kit and appear to be pegged up there (actually the concentration has gone higher than the test can read.) The phase prior to that (which you are in now) is when ammonia is still working up to the point where it can clear in 24 hours and perhaps nitrite has begun to appear in amounts less than the spike.

The final phase after the nitrite spike is after nitrite is falling back to zero ppm within 24 hours. At some point during this last phase you begin doing an extra test set at the 12 hour mark to see how many hours its taking to clear the toxins. Once they both clear to zero ppm within 12 hours, you've hit the big day where you can start your Qualifying week and verify that you are ready for the big final water change and fish.

~~waterdrop~~

 

[Katch]

Ammonia nearly down to 0 today so added 4ml of 9.5% Ammonia.

Nitrites not quite spiked yet at ~1.5 still on the chart. Nitrates appear to be heading off the chart if not already there.

pH dropping a little so added 1/2 tsp of bicarb.

I'm away from Thursday afternoon untill Monday night - how quickly is the Ammonia likely to cycle at this stage and should I try and arrange for someone to dose the tank or just bring it up to 5ppm on Thursday before I go?

Also, with my qualifying week should I do a 90% water change - continue dosing 5ppm every 24 hours and check for zeros after 12 hours and then at the end of the week do another water change before the fish?

!Snail edit! - We have life, just saw a little trumpet snail exploring my tank. Must have hitched in on one of the plants.

 

[waterdrop]

If the ammonia is now dropping from 5ppm to zero ppm within the 24 hours of each day and you are re-dosing each day at your "add-hour" then yes, it would be good to have someone come in and dose, or at least dose once in the middle of your absence. It will probably recover ok though if you can't manage that.

Large (90%) water changes are often an option, mostly in the third phase of fishless cycling depending on a number of conditions. If you suffer a pH crash of course, a large water change is the first remedy, even if you are going to dose bicarb. Another reason for the occasional large water change is to clear nitric acid, which is a small percentage component of having high nitrates(NO3) due to the high dosing rate of fishless cycling. Both high nitrites and high nitrates have a (slight and possible) negative effect on N-Bac growth. One bother of water changes during fishless cycle though is that it can take a while for the stats to settle down afterward and really be showing you what's going on as opposed to a tank cleaned out by the water change.

~~waterdrop~~

 

[LondonguyJ]

Congrats on the nitrites

Remember to keep an eye on your Nitrates and Ph. A high nitrate count can crash your ph to below 6.0 almost overnight. Slowing the cycling progress altogether.

J

 

[Katch]

So,

came home this morning and tested the water.

Ammonia ZERO; that's 4ml of 9.5% ammonia to zero in under 24 hours. Nitrates and nitrites off the scale.

So I added another 4ml.

I then thought I should probably check my pH - test came back worryingly dark maybe not far off 9. Concerned that this is too high I performed a 50% w/c (dosing the water with Tetra Aquasafe) - added another 1.5ml of ammonia to bring the test result back up to around 3ppm. pH is now not much more than 8.

Did I do the right thing? Have I been a little too generous with the bicarb or did the ammonia dose make the pH rocket?

 

[waterdrop]

It was probably the bicarb and the ammonia together and you did the right thing to optimize.. either way you are doing fine. WD