How to know if your tank is cycling...

[zozo]

The answer to the question "How to know if your tank is cycling..." is always a bit vague, i even doubt if it can be adressed with one all combining short answer, without rewriting the complete Diana Walstad books.. 🙂

Your tank will start cycling from the moment you put water in it and the bacteria start to multiply.

The way cycling an aquarium is explained sometimes is a bit distracting and is stated if the ammoinia and nitrite peakes are over the tank is cycled. But actualy this should be changed in "the tank is from that point on safe enough to put lifestock in". 🙂 In general it is advised to setup an aquarium, put water in it and let it run for a number of weeks before lifestock is put in. This to give the nitrifying bacteria a while to multiply to sufficient numbers before extra waste (ammonia = pooping critters) are added.

Bottom line is an aquarium starts to cycle from day 1 it is setup and it will never stop doing that til the day it dies. The way it is cycling depends on a lot of external factors with many variables you just can not give a number to.. For example, a dirt substrate aquarium will start to cycle in a slightly different way than a tank setup with sand only.

 

[AlexH]

what are the tap water values?


unlikely - it's actually quite difficult to "kill" bacteria, though you can slow them down substantially ("bacteriostat" vs "bacteriocide")

I'm a but dubious of the claims to "read" (measure) various compounds to the degree of accuracy implied by that decimal reading, ie
1.0
1.2
0.8
7.8
etc

What value do you get when you perform sample readings in duplicate? triplicate?

Test 1
remove volume of water from tank & test for ammonia, nitrite, nitrate in duplicate (report values)

Test 2
remove a second sample of water from tank & test for ammonia, nitrite, nitrate in duplicate

Test 3
repeat Tests 1 & 2 using tap water in place of tank water
- this should give you "control" or "background" readings

Test 5
Check kits readings/your technique using the positive standards supplied with test kits, eg ammonia, nitrite, nitrate
(if there are none, look for test kits that include these)

Test 6
Add ammonia to tank to provide an expected 2 ppm ammonia
- check tank water for ammonia, nitrite, nitrate values

Add ammonia to tank to provide an expected 4ppm ammonia
- check tank water values

Doing all of this will give you an idea of how accurate/relevant your present data is.

This is great thanks.

The decimals are my estimates when i compare my readings to the standarised colour charts - i never thought to compare my results with a set of control readings.

When you make ref to duplicates... to be clear; when testing water, i should test it numerously?

Thanks

 

[Costa]

@OP
Why are you doing water changes in a fishless tank cycling?? The idea of cycling is to use the high NH4 and NH3 to your advantage, i.e. give time for ammonia-eating bacteria to appear, multiply and colonize your filter media. If you do water changes you are taking away the bacteria that have grown in your water and their food (ammonia, nitrate, nitrite).

You should be monitoring NH4 and NH3 and once these start going down (due to bacteria consuming i then also start monitoring nitrates. Do NOT do water changes while cycling your tank and filter media!

 

[AlexH]

@OP
Why are you doing water changes in a fishless tank cycling?? The idea of cycling is to use the high NH4 and NH3 to your advantage, i.e. give time for ammonia-eating bacteria to appear, multiply and colonize your filter media. If you do water changes you are taking away the bacteria that have grown in your water and their food (ammonia, nitrate, nitrite).

You should be monitoring NH4 and NH3 and once these start going down (due to bacteria consuming i then also start monitoring nitrates. Do NOT do water changes while cycling your tank and filter media!

I did think that but TGM recommended the WCs on a weekly basis!

 

[Costa]

If you had like over 10ppm NH4 I would also do a water change, but with the concentrations you reported the water changes are simply taking away all the food source of your good bacteria and as a result it will take ages for them to grow and colonize your filter. I would leave the tank cycle without any water changes. If you keep removing the NH4 & NH3, how is the cycle going to be completed? Not to mention that you are also removing the bacteria that have been growing in your tank water.

As soon as NH4 drops to ~0, you will see a peak of NO2, after a while the NO2 will read zero and you will get a peak of NO3 - at this point your filter is colonized with good bacteria and you have to do a big water change to bring the NO3 to ca 20ppm (definitelly no more than 50ppm).

Now you must gradually add fish, because you need a continuous source of ammonia. Of course your substrate is giving out ammonia but not at the intial rate, which means that if NH4 gets depleted, the bacteria have nothing to feed on, they die, NO3 spikes and that kills your fish.

If you want to accelerate the process, you may use some commercially available bacteria products (Sera bio-nitrivec for e.g.) which people have used with good success.

 

[alto]

When you make ref to duplicates... to be clear; when testing water, i should test it numerously?

yes, this will give you a "read" on how reproducible your own actions are

It's much simpler if you've a positive control solution (usually something that is mid range on the test kit range) as this removes some other variables from the process.

 

[AlexH]

If you had like over 10ppm NH4 I would also do a water change, but with the concentrations you reported the water changes are simply taking away all the food source of your good bacteria and as a result it will take ages for them to grow and colonize your filter. I would leave the tank cycle without any water changes. If you keep removing the NH4 & NH3, how is the cycle going to be completed? Not to mention that you are also removing the bacteria that have been growing in your tank water.

As soon as NH4 drops to ~0, you will see a peak of NO2, after a while the NO2 will read zero and you will get a peak of NO3 - at this point your filter is colonized with good bacteria and you have to do a big water change to bring the NO3 to ca 20ppm (definitelly no more than 50ppm).

Now you must gradually add fish, because you need a continuous source of ammonia. Of course your substrate is giving out ammonia but not at the intial rate, which means that if NH4 gets depleted, the bacteria have nothing to feed on, they die, NO3 spikes and that kills your fish.

If you want to accelerate the process, you may use some commercially available bacteria products (Sera bio-nitrivec for e.g.) which people have used with good success.

This makes complete sense. Of course, when the people who are experts advise you contrary, it causes confusion.

Thank you for spending the time to give such a thorough response.

 

[sciencefiction]

I found it somewhere here in seachem support forum in FAQ where seachem administrator answers a given questions...

http://www.seachem.com/support/forums/forum/general-discussion/1803-prime-questions

The only reference about timing in relation to the de-chlorination process in that link is:

"10-14-2011, 16:36
Re: Prime questions...

You are welcome!

1. Prime works immediately upon adding it to the water.

2. Prime works immediately regardless of the water's pH.

I hope this helps!"

To me this just sounds as if Prime becomes active immediately, which it should but it does not mean the process is all over in 2 minutes.

 

[Costa]

This makes complete sense. Of course, when the people who are experts advise you contrary, it causes confusion.

Thank you for spending the time to give such a thorough response.

Pleasure. I, too, started from zero. If you browse through the forum you'll find that I ask a lot of questions. Don't be afraid to ask and good luck with your tank.

Costa

 

[tadabis]

The only reference about timing in relation to the de-chlorination process in that link is:

"10-14-2011, 16:36
Re: Prime questions...

You are welcome!

1. Prime works immediately upon adding it to the water.

2. Prime works immediately regardless of the water's pH.

I hope this helps!"

To me this just sounds as if Prime becomes active immediately, which it should but it does not mean the process is all over in 2 minutes.

Maybe you are right... I was reading (googling lots of threads about Prime) and maybe my collected information mixed in my head 🙂 anyway thank you for answers!

 

[dw1305]

Hi all,

which means that if NH4 gets depleted, the bacteria have nothing to feed on, they die, NO3 spikes and that kills your fish.

Get a way with you. Honestly this isn't true. Nearly all the "facts" (that you read on forums) about cycling are wrong and based on a series of half-truths and misunderstanding.

Have a look at <"Oxygen levels required..."> and <"New tank, leave it? or not?">. (from the latter)

"Cycled" or "not cycled" isn't really a very useful concept. There isn't a sudden switch from "toxic" to "fish safe", in all biological filtration systems there is a continuum from no capability to deal with ammonia & nitrite through to the ability to process wastes with enormous <"Biochemical Oxygen Demand"> (BOD). BOD is the prime metric, and we are really interested in <"oxygen"> (filtration bit is towards the end) and not ammonia at all.

The advantage of plants is that they are net oxygen producers, they directly take up ammonia, and they create a much larger area for microbial colonisation, because of this plant/microbe filtration systems can potentially deal with about an order of magnitude more bioload than microbe only systems can.

There is a pretty exhaustive discussion of cycling in <"Best way to cycle...">

cheers Darrel

 

[Manisha]

Hi Alex, I thought I'd mention with Amazonia you've two processes happening with a fishless cycle - the ordinary filter establishing bacteria & huge ammonia leeching! Even with an established setup & adding ADA AS the second process may take 4-8 weeks (depending on batch)Because of the latter, water changes are essential despite how inconvenient! The leeching process keeps your ammonia at high levels during this period & there is little you can do to prevent this.

Hi all,Get a way with you.

Darrel humour is few & far between, but priceless however 😀 😀 we were all silly once!

 

[AlexH]

Hi Alex, I thought I'd mention with Amazonia you've two processes happening with a fishless cycle - the ordinary filter establishing bacteria & huge ammonia leeching! Even with an established setup & adding ADA AS the second process may take 4-8 weeks (depending on batch)Because of the latter, water changes are essential despite how inconvenient! The leeching process keeps your ammonia at high levels during this period & there is little you can do to prevent this.



Darrel humour is few & far between, but priceless however 😀 😀 we were all silly once!

Lol now im confused again :,)

Ive done two big 90% WCs but ive been told i shouldnt have as in essentially removing bacteria and its food....

Please assist 🙂

Thanks!
Alex

 

[sciencefiction]

I come from the old school of people that did fishless cycling from scratch with no mature media and by dosing ammonia.
In all the fishless cycles I've done, the process was all over and safe for fish in about 4 weeks.

It takes about 7 days for the tank to convert around 3ppm ammonia every 24hrs. After that you get the nitrite spike and it is then you need to do the water changes because it goes into the tens and hundred ppm range and you might as well wait half a year for these levels to convert to nitrates. There will be never such levels of nitrite in a normal aquarium at once.

But this is based on controlled dosing of ammonia and not from soil leaching ammonia...

So I'd do 90% water changes during cycling if the ammonia is over around 4ppm range. You can't leave huge amounts of ammonia in there because you end up with massive nitrite levels which won't go away for ages..High ammonia levels may also inhibit the same bacteria you are trying to culture.

If the ammonia stays at around 3ppm-4ppm max, I'd just leave the tank alone. Do the water change if the nitrites start spiking beyond the test limit, which they will if the ammonia was way too much in the first place. And do water changes if you have soft water as the Kh will rapidly go down and crash the Ph. Then the cycle will go on for months....It takes a lot longer to cycle a soft water tank but planting helps to reduce the ammonia and the ammonia is non-toxic in soft water so people get away with stocking these tanks early.

As far as removing all the ammonia via water changes, it is possible to remove too much and one just slows down the cycle that way if the majority is always removed. But soil is supposed to leach ammonia constantly so lots of it goes undetected as the cycle pretty much starts within a day or two.

Those that claim it takes way longer for the nitrite stage are pretty much wrong. Its simply because after bombarding the system with so much ammonia, the levels of nitrites have gone so massive, it takes weeks for enough bacteria to grow to bring them down. But we're aren't going to keep whales in the tanks.... It pretty much takes one week for the ammonia stage and two weeks for the nitrite stage. The 4th week is for safety....Then I stock fully if I know the system has converted 3-4ppm ammonia a day for the lats few days and all levels are at 0 after 12-24hrs.

Then I change all the water in the tank and its ready for fish. I've never lost new fish in a tank cycled like that, even sensitive ones.

Cycling with soil and plants is exactly the same process with that difference you can't control the ammonia levels.....There's no difference otherwise and I've cycled fishlessly a tank with plants without any issues whatsoever. So again those that claim the high levels of ammonia kill plants, are wrong too...Ammonia is ammonia, whether from fish, from soil or from a bottle. Plants love it...as long as you stick to 3ppm max at any time during cycling.

 

[Costa]

Get a way with you. Honestly this isn't true. Nearly all the "facts" (that you read on forums) about cycling are wrong and based on a series of half-truths and misunderstanding.

I'm not sure how to counter this, except by pointing out that I've followed the process I described for all my tanks and never lost a fish upon introduction to the new tanks and the 1,5 years the tanks have been running.

Of course every tank is unique, I am based in Greece where for the most part the water is much harder than what you have in the UK, so that might be a factor. On the other hand, I keep tetras which aren't the most hardy of fish.

I humbly offer my advice based on my experience over the 2 years I've been involved with the hobby, I sure as hell don't know it all

 

[alto]

Ive done two big 90% WCs but ive been told i shouldnt have as in essentially removing bacteria and its food....

If that were true, my tanks would be "barren" 😀
I've done essentially complete water changes (think multiple 90%) when rescaping tanks etc & filters/tanks certainly remained "cycled"

It's been a long time since I've set up any tanks without having some sort of media from a previous set up ...
I did a break of a couple years at one point, storing filter media damp in canisters ... when I finally set the tanks going again, they "smelled" like cycled tanks within a few days.
Further I'm lazy so I just used Seachem's Ammonia Alert & 5in1 test strips (not my preferred brand but they're OK) to monitor nitrogens: ammonia never measured above "Alert" status, nitrites remained "undetected" (API strips are not as sensitive as some other brands), nitrates detected after a few days (I'm just tossing in some fish food)
I used Tropica Growth Substrate & Aquarium Soil, plants put in at start, shrimp & otocinclus added at ~Day 7, then fish after a few weeks.

 

[dw1305]

Hi all,

I'm not sure how to counter this, except by pointing out that I've followed the process I described for all my tanks and never lost a fish upon introduction to the new tanks and the 1,5 years the tanks have been running.

Yes, you can successfully "cycle" a tank with ammonia, but you can also just leave a planted, filtered tank to establish over ~6 weeks.

The main point is that the principal metric that limits nitrification (biological filtration) isn't the availability of ammonia, it is the availability of oxygen. Because of this, as scientists, we quantify the level of pollution using the Biochemical Oxygen Demand (BOD).

Like Marcel (Zozo) says there isn't a binary switch from non-cycled to cycled, there is a continuum, dependent upon the bioload your system can cope with. As a general rule planted tanks with floating and emergent plants (plant microbe systems) and a large gas exchange surface are about an order of magnitude more efficient at nitrification than microbe only systems.

Have a look through the linked threads (and links): <"Oxygen levels required..."> and <"New tank, leave it? or not?"> for some more details.

cheers Darrel

 

[sciencefiction]

Biochemical Oxygen Demand (BOD).

I agree that a functional planted tank is way more capable of dealing with heavy bioload. I am wondering though, isn't the oxygen content more compromised in a new tank with organic rich soil then it is in an inert substrate planted tank cycled with ammonia?

The oxygen content can plummet really dangerously in a soil tank when starting it up if one doesn't ensure sufficient oxygenation by other means rather than plants.

Most of the floating plants people keep really struggle with "large gas exchange" because the latter is achieved by vigorous surface movement and the floaters do very badly with that in my personal experience. That's how I always killed my floaters, especially the frogbit as its roots got caught pulling the leaves underwater. For that reason I find emersed plants with their roots only in water more practical in consuming excess nitrogen.

 

[dw1305]

Hi all,

I am wondering though, isn't the oxygen content more compromised in a new tank with organic rich soil then it is in an inert substrate planted tank cycled with ammonia?

Yes it would be. Because of the oxidisation of the organic matter in the flooded soil the aquarium could potentially have a very large BOD.

The nature of the carbon (C), and the availability of nitrogen (N), would become important then. If the nitrogen level was low, and/or the carbon relatively inaccessible structural carbohydrates (like lignin), then you still wouldn't have a huge BOD.

There is discussion here: <"Is organic matter...">.

The oxygen content can plummet really dangerously in a soil tank when starting it up if one doesn't ensure sufficient oxygenation by other means rather than plants.

In the case of starting a soil tank I would want as much oxygenation as possible. I think this is a situation where I would definitely favour a wet and dry trickle filter, and best of all a planted wet and dry trickle filter.

For that reason I find emersed plants with their roots only in water more practical in consuming excess nitrogen.

Emergent plants probably are the optimal solution if you can use fit them in.

cheers Darrel

 

[AlexH]

Okay so...

Further to my last readings.

I undertook a 95% water change on Friday just gone.

Ive just tested my water parameters today.

On my tap water control - I got 0 for both ammonia and nitrite.

I did two sets of water tests for each - both returned identicle results.

Ammonia - between 0 - 0.6
Nitrite - between 0.3 - 0.8

Theyre significantly reduced from my previous... good sign?

Thanks!
Alex