Almost There... Now What?

[MartinL]

Ok, I have been going through the fishless cycle (add & wait) for that last few weeks, and and now seeing the nitrIte reading (having been over 20ppm previously) dropped down to almost 0 (the faintest tinge of violet) 24 hours after adding 5ppm Ammonia. Ammonia is 0 after 24 hrs. NitrAtes are sky high.
So... I am going to test after 12 hours, and if I am reading the advice on here correctly, once I get a weeks worth of 0 Ammonia and NitrIte readings I do a 90% water change, drop the temp down to 24/25 ish than am cycled. True?
After that... what?
The tank at the moment has a few slate rocks in it, and a few artificial plants, but they are all covered in brown 'stuff', which I believe is normal due to high nitrAtes. Do I take the decor out and scrub clean when I fo the water change, or will it disappear by itself?
I am going to transfer some fish from a smaller tank to this one (this one is 180l), and get some more too. Should I stock up to full capacity, or start with a few and work up. I was going to use the old tank as a quarantine tank - is this worthwhile? If I do, then will I then have to go through a mini-cycle again once I add them to the main tank?

All comments gratefully received!

 

[toshapetriji]

Congratulations on getting this far.

Yes you are right the wait for a week to ensure that the ammonia and nitrite continue to fall to zero.

After I completed my cycle I removed all stones etc and scrubbed them clean as well as all tank surfaces. Then did a 90% water change to get those Nitrates down.

I stocked to about 80% capacity at this point. Some advise that this is too much but my rational was that by doing the fishless cycly I was building up enough bacteria to handle this load OK. Indeed I have not lost any fish and ammonia and nitrite readings have always remain at zero.

Certainly you can use your old tank for quarantine. Adding extra load to any tank will cause a mini cycle but if you have a filter working correctly then it will very quickly catch up. You may not even notice the cycle at all.

Anyway I hope this helps and enjoy your new hobby.

 

[waterdrop]

Hi Martin,

A careful reading of your post seems to reveal that you've been through the stage of nitrites(NO2) staying spiked sky high and now are excited that nitrites are falling, for the first time, all the way to zero by the time you measure 24 hours later.

This is indeed a nice milestone, as it tells you the N-Bacs (nitrite oxidizing bacteria) have multiplied to the point where their population can eat up the big backlog on nitrite and turn it into nitrate(NO3).

But the next milestone you need to confirm is whether the N-Bac population can yet lower the nitrites(NO2) down to zero within *12 hours or less*, which is the signal to start your "qualification week." Now, if you were only running your test regimen once a day, you may indeed have reached that point, but you need to time it and find out.

If you find its taking them -longer- than 12 hours and seems to get stuck in this period, you may want to consider doing a 90% water change (with gravel clean and ammonia recharge) in order to get that very high nitrate(NO3) level down, as that can cause N-Bac growth to slow. On the other hand, the very ending stages (getting nitrites to drop to zero in under 12 hours) can be a final, very slow, frustration for many fishless cyclers, so be aware you are not alone if this is the case. It *will* eventually do exactly what it is supposed to do and allow you to do your "qualifying week."

~~waterdrop~~

 

[MartinL]

Thanks for the advice
Have been testing after 12 hours for last 2 days, (adding Ammonia to 5ppm at 06:00 and testing at 18:00) and Nitrite is not 0 yet - reading about 1-2 ppm.
I didn't know that high NitrAtes can cause a stall in Nitrite bacteria production. I will do a large water change/tank clean when I get the chance - may not be tonight though. Presumably if I do this now, and assuming nitrites drop in the next few days, I won't need to do this again at the end of the cycle unless NitrAtes rocket in the next few days? As a rough guide, what is an 'acceptable' level of NitrAte to maintain the tank at? Just so I can plan my water change maintenance schedule.
Thanks

 

[waterdrop]

You *always* need to do the 90% water change at the end of fishless cycling. Think of it as throwing out the bacterial growing "soup" and putting in the first week of fresh fish water!

Among other things, one of the things we're trying to do here in the beginners section is get people used to the habits that the experienced fishkeepers have found to be the most important in the hobby. Very high on that list (again, this is beginner oriented, so not to say you won't find controversey among long-timers!) is lowering the mental barrier to doing significant water changes. Most beginners are much better off if the get comfortable with the idea that tank water should come out frequently and get replaced with tap water (conditioned and rough temp matched.) A weekly habit of a gravel clean water change is much more on target with the rhythm of good tank maintenance that anything less.

Nitrates(NO3) are not so bad in and of themselves and in fact when we get into "sciency" discussions we can find instances where fish were not killed by exposure to 1000ppm (one thousand parts per million) if I remember correctly (or, there was another discussion where 400ppm was cited.) For the beginner, these kinds of discussions are truly misleading and academic in my mind, as our use for nitrate(NO3) testing is more about using it as a "canary in the coal mine." If we're in a situation where we see nitrate high, its a good reminder that *other* things like various metals and trace organics are possibly too high also. All these "other" things are way too esoteric and expensive and difficult for us to test for, but the easy solution is to throw them out and start again with fresh tap water, or, actually, we can think of it as an -exchange- of excess of certain substances and a deficit of other needed substances. Often another positive of this fresh water is a fresh dose of calcium carbonate and other desirable substances which fish use to maintain balanced cell pressure and plants and bacteria use for cell building.

As far as giving you a -number- that's desirable for nitrate(NO3) level, you can see more now why that's hard to do and maybe even not really so important, but often we cite 20ppm-above-tap-nitrate-level in order to give beginners a number. As an example, in my own tank I measured nitrates jumping around all over the place, including some very high readings, during fishless cycling and shortly after. Then nitrates settled down to about 20ppm (my tap nitrates are zero) and finally, somewhat later, they've settled down to NO3=10ppm and stayed there.

Hope this helps some with your question,
~~waterdrop~~

 

[MartinL]

Waterdrop - Thanks for the quick reply.
I will follow your advice and do another large change when the tank is fully cycled.

So... without wanting to pin you down to a specific number, as a rough guide we are looking to change the water on a schedule to keep NitrAtes below 20ppm?
I plan to be doing weekly water changes, so will calculate how much I need to change when I get the fish in the tank... probably too soon to be getting specific when they are all in the LFS at the moment!

Can you tell me how much NitrAte is produced by 5ppm Ammonia? I have read that 1ppm Ammonia makes approx 2.4ppm NitrIte, but have you any idea what this converts to in NitrAte?

Also... sorry for asking so many questions, but now I have your attention... why do we cycle with 5ppm Ammonia? Is this calculated to be the average output of a fully stocked tank?
Thanks


To answer my own last question I have just seen this on a post from Miss Wiggle
"the theory is that after a fishless cycle your filter can cope with a full 5ppm of ammonia every day which is more than a full load of fish"

 

[waterdrop]

Right, you've generally answered your own question there. Arriving at 5ppm as the current recommended final dosing is actually a composite of things. The most important is indeed that 5ppm respresents a bit more than a very full stocking, allowing it to handle the rare case where a fishless cycler would actually put a lot of fish in right away (extremely rare though!) But the other thing to realize is that starting high and going down is really the only approach you can take as the other way 'round doesn't work, you can't have your bacterial population too low and then magically bring it "up." And you are never going to have an exact match of bacterial population to fish population before they've been together for some period of time!

So, not only must you start with a higher than needed bacterial population and let it naturally drop itself down to match your fish load (which of course it does as a natural consequence of matching its ammonia food level), but there's also in intangible "robustness" factor, I feel, to describe numerous observations that newly built up bacterial populations are somehow not as robust as older, longer running populations in our filters. When bacteriologists study biofilm structure and bacterial population growth and senescence, they describe many more complicated considerations than we are taking into account in our simplified generalizations used in the hobby.

In essence, I feel the recommendation we've built up is that there's a certain level of this "robustness" we seek in the new filter colonies and that there is a much greater assurance of this if we verify that 5ppm of ammonia added initially is dropping to both zero ppm ammonia and zero ppm nitrite(NO2) in 12 hours or less and that we then repeat this for a full (or at least majority of the days, say to get you to the weekend, lol) "qualifying" week. The business about having this week came about because in a certain number of cases it was found the filter would still "mini-cycle" when presented with a load of fish, despite having reached the day of 12-hour drops, so to speak.

To address one of your other questions: One ppm of ammonia is converted to 2.7ppm of nitrite(NO2) by the A-Bacs. Then, the N-Bacs convert nitrite(NO2) to nitrate(NO3) at an even higher multiplication factor, but I forget the exact figure, so maybe some member will confirm or correct me... I believe its that 1ppm of nitrite(NO2) is converted by the N-Bacs to 3.6ppm of nitrate(NO3.) This, of course, explains why the "nitrite spike" happens in the second phase of fishless cycling and why fishless cyclers get large amounts of nitrate(NO3) buildup, much more than they will get once they have a normally funtioning tank.

Your deduction of 20ppm as the water change trigger level for nitrate(NO3) is almost correct. The better way to always state it is to say that you are usually looking for "20ppm above tap water level", since there are plenty of people with nitrates in their tap water which will give them a higher starting baseline. And again, its important to understand that its the "trend" that's of significance, not the numerical figure. You want to use, as a beginner, somewhat frequent tests to establish a "feel" for your nitrate level and then be able to know later whether something has caused them to drift upward or downward. This drift direction can be used to fine-tune your water change regimen, rather than some adherence to a particular number. Its valuable to give beginners some numbers, or a "ballpark", like 20ppm or 40ppm or "under 80ppm" but understanding this paragraph is the better knowledge, rather than one of the numbers.

[--addendum-- At the risk of taking you even farther afield I will add that many guidelines and things we talk about in the beginners section are in fact (on a grander, almost philosophical scale) purposefully generalized to a sort of "freshwater tropical beginner lets-get-them-on-their-feet-walking" ( ) approach. The hobby as a whole is much broader and even more "experimental" than the simple picture the beginners section paints. There are species-specific tanks that can have decidedly different maintenance regimens and there are, to give one of the quite popular examples, whole branches that are nearly diffrerent hobbies in and of themselves, like the hobby of "planted tanks." In the case of planted tanks, there are at least two major branches (I'll just generalize them to "high-tech" vs. "simple/natural" (both are usually used to create "visually natural looking aquascapes", the "simple/natural" only refers to a technique meant to acheive this) that each have a history of success on various levels.

There is considerable overlap among the hobbyists practicing bits of these different approaches to the hobby, leaving lots of opportunity for beginners to hear confusing contradictions from legitimately experienced advice offerers! It is my sincere feeling that having some specific middle-of-the-road advice to offer beginners is of great value in getting them started, and so I participate in passing on this sort of information, but its also important, I think, to periodically offer the sort of "disclaimer" I'm attempting to give here. TFF is, in my opinion, a great set of forums partly for having this sort of solid grounding for beginners but also for having lots of advanced interest forums and lots of experienced people from those who come dodging in with interesting perspectives! --end of addendum--!]

~~wordywaterdrop~~

 

[MartinL]

WD - Thanks for taking the time and effort to write such a detailed reply!
Food for thought.

The latest...
The Nitrite readings were still around 2ppm when I checked them last night after 12 hours, so I did a large water change and tank cleanup. After the change the NitrAte reading was 20ppm so it must have been in the 200ppm range previously.
Added the ammonia this morning at 06:00 and will test again at 18:00. Fingers crossed!

Martin

 

[toshapetriji]

Seems you are getting there. Be patient and all will be well for your new friends.

 

[waterdrop]

 

[MartinL]

Sigh....
Last night's results were:
Ammonia 1ppm ! (first time I have seen any for ages)
NitrItes 2ppm

I think the clean may have taken away some bacteria living in the substrate/on the rocks?

So it's one step forward, 2 steps back at the moment.
Will keep going - hopefully get some fish in there before Xmas... but not holding my breath.

 

[waterdrop]

Actually, you may be more literally correct than you might have expected. In my experience we usually expect about a 2 day stall on a cycle process after a cleaning. Growing bacterial colonies do not like to be disturbed. But of course there are times when we need to disturb the situation because we know in the longer run we'll get the cycle process back on track to do better.

To me your test results are well-timed for your learning. One of the reasons for my first post "a careful reading" was that I feel I could point to 100 cyclers who go through this exact same turn in the road. The nitrite spike finally begins to drop and they can't help but get very excited that the end is near, only to find out that the stubborn N-Bacs are going to try their patience in the extreme during the "end-game." Patience can wear very thin trying to get through the part where they can clear nitrites to zero in 12 hours and where the whole thing is stable enough to pass a "qualifying week."

The "big win" to keep in mind though is that if you can discipline yourself to achieve that, it can almost be guaranteed that your biofilter will be rock solid for a long time after that, hopefully more or less "forever" if well-maintained! And think(!), forever after you will have "mature media" for any future new filters!

~~waterdrop~~