Nitrogen Cycle for Aquariums / How NOT to kill all your fish with your first tank

Ola

Here's a 'copy & paste' (IOW, it's not mine) on the nitrogen cycle...some info for the noobs.

NOTE - I got it off another aquatic forum approximately a year ago. The owner of the below document is no longer a member on that forum and the original document/thread/article has also been removed. All credit of the info below goes to the original author and in no way do I claim this information as my own.

Nitrogen Cycle

If one does not understand the nitrogen cycle, one does not understand fish keeping. It is the first thing that should be explained to you when you purchase your new tank setup from your local pet shop. Those of you that purchase your setup from your local hypermarket must not expect any help from the pet shops. It is up to your supplier to provide you with the correct information in setting up your aquarium correctly. Your initial purchase from the hypermarket might be cheaper, but in the long run its going to cost you more in fish than you saved on your purchase. The first thing to learn in fish keeping is patience. Being impatient will be a costly exercise. Patience is required while your new aquarium is cycling (and that does not mean riding a bicycle).

This is the time when most novice aquarists (including some pet shop owners) endure massive losses without having a clue as to what is wrong and ultimately become discouraged and leave this enthralling hobby. It takes approx. 31 days for the nitrogen cycle to complete, which means that you can't fully stock your aquarium till then.

Your aquarium in its new state is basically a sterile environment. After adding water, then Bio-Elite antichlor, you can then add fish and plants after stabilising the temperature, if keeping warm water tropical fish. This is when the fun begins. Like it or not, fish have to breathe in water which it then passes over its gills, removing some oxygen and exhaling carbon dioxide and ammonia. Fish also excrete urine and faeces. The urine contains ammonia while the faeces drops to the bottom where decay bacteria breaks it down into ammonia and other by-products. Dead fish and plants are also broken down by decay bacteria to produce ammonia. Dead bacteria also break down into ammonia. So we see that we have a great ammonia manufacturing factory in our aquarium. Unfortunately, ammonia at low levels is extremely lethal to fish.



There are only 2 ways of reducing this lethal ammonia, the first is to chemically remove the ammonia using zeolite (often called ammonia remover) and the second is biologically. The preferred method is by biological removal by promoting nitrosomonas populations. Most ammonia removers, though rechargeable, never show a colour change, so there is no way of knowing when the product stops working.

Once the ammonia levels start building up, nature now provides the nitrosomonas bacteria to "feed" upon the ammonia. This is an aerobic (just means that it needs oxygen) bacteria. In order to survive it needs oxygen and its food source which is ammonia. Nitrosomonas bacteria are slow to replicate. In fresh water they tend to replicate geometrically every 8 hours i.e. after 8 hours we have 2, then 4 (16 hours), then 8 (24 hours) ect. Salt water slows the reproductive rate to about once every 24 hours. We see therefore that ammonia is necessary to trigger off the nitrosomonas bacteria, so it is hard to understand why some pet shops tell their clients to leave the aquarium standing for 2 weeks before they add fish. Dechlorinators are available to remove chlorine and chloramines and if we cannot afford the dechlorinators, we shouldn't be keeping fish in the first place. So the sooner we add fish etc to the aquarium, the sooner we trigger off the nitrogen cycle.

As is nature’s way, if something feeds on something, sooner or later it will have to excrete something. In this case the nitrosomonas bacteria now excretes nitrite and the nitrite levels, also toxic to fish but not as deadly as ammonia, starts to build up. A second beneficial bacteria called nitrobacter bacteria is now needed to reduce the nitrite levels.

We now encounter another problem and that is that the ammonia present inhibits the growth of the nitobacter bacteria. This is the reason why we first get an ammonia peak (anywhere up to 10 days) followed by a nitrite peak (usually from 14 to 31 days) after the introduction of our new fish to the aquarium. This incidentally is termed new tank syndrome which is nothing more than the ammonia and nitrite levels peaking.
After the approx 10 days, our ammonia levels should now have returned to zero and out nitrobacter bacteria can now start to reproduce until we get to a level where there is sufficient nitobacter bacteria to keep out nitrite levels at zero.
Again we have the nitrobacter bacteria feeding on nitrite and the something that it now excretes is nitrate which is the final by-product of the nitrogen cycle. Fortunately for us nitrates have to get to very high levels before it starts affecting the fish. It can be reduced by anaerobic (doesn't need oxygen) bacteria which converts to nitrogen which is a gas likened to the other final by-product in humans commonly known as farting.
Nitrates can be more effectively controlled by water changes as anaerobic bacteria is difficult to control and if not controlled properly can lead to hydrogen sulphide (really smelly) being released into the water by means of bubbles.

Hopefully we will now realise that at some time or other, you might have been conned into using Hagen's cycle product as a "magic potion" where you were led to believe that a culture of bacteria was added and suddenly the Nitrogen Cycle's run in period was eliminated. Cycle will reduce the ammonia and nitrite spikes if used correctly. Because ammonia inhibits the nitrobacter bacteria, cycle must be regularly added to the aquarium and not in one single dose as most pet shops are advocating. You can save yourself approx R70 by merely adding a handful of gravel from an existing "run in" aquarium every week until your nitrosomonas and nitribacter bacteria are at the correct levels.

The nitrifying bacteria prefer alkaline environments (p.h. 7.2-8.5). It is important to have a stable ph level. The nitrifying bacteria are also most active at temperatures ranging from 20 degrees C to 30 degrees C. Below 15 degrees C and above 35 C, the bacteria will start dying off. We see therefore that our pond keepers must be careful in spring not to increase their feed loads too quickly as our nitrifying bacteria has to increase their levels as the water warms up. The koi and goldfish will increase their activity and feed as soon as the water starts to warm, but because of the slow rate of reproduction of the nitrosomonas and nitrobacter bacteria, do not increase the feed too quickly.

Please also remember that an established aquarium can cycle at any time, depending on the severe changes of the bio load, filtration failure or any loss of the nitrifying bacteria.

I hope that this article has helped you to understand the nitrogen cycle and that I have once again helped to reduce the cost and upkeep of your hobby.

***

Hope this helped

Cheers
Dale

 

Here's another, easy to follow guide through on the cycle process i found on www.phish.co.za

as i read through it i thought it'd be good to share this for anyone interested:

The Nitrogen Cycle Written by Support Saturday, 01 March 2008

Nitrification​

Call it cycling, nitrification, biological cycle, startup cycle, break-in cycle, or the nitrogen cycle. No matter what name you use, every newly set up aquarium goes through a process of establishing beneficial bacterial colonies. Older aquariums also go through periods during which the bacterial colonies fluctuate. Failure to understand this process is the largest contributing factor to the loss of fish.
Learning what it is, and how to deal with critical periods during the nitrogen cycle, will greatly increase your chances of successful fish keeping. The Waste Problem

Unlike nature, an aquarium is a closed environment. All the wastes excreted from the fish, uneaten food, and decaying plants stay inside the tank. If nothing eliminated those wastes, your beautiful aquarium would turn into a cesspool in no time at all.
Actually, for a short period of time, a new aquarium does become a toxic cesspool. The water may look clear, but don't be fooled. It's loaded with toxins. Sounds awful, doesn't it? Fortunately bacteria that are capable of converting wastes to safer by-products begin growing in the tank as soon as fish are added. Unfortunately there aren't enough bacteria to eliminate all the toxins immediately, so for a period of several weeks to a month or more, your fish are at risk.
However, you need not lose them. Armed with an understanding of how the nitrogen cycle works and knowing the proper steps to take, you can sail through the break-in cycle with very few problems.
Stages of the Nitrogen Cycle

There are three stages of the nitrogen cycle, each of which presents different challenges:
1: The cycle begins when fish are introduced to the aquarium. Their faeces, urine, as well as any uneaten food, are quickly broken down into either ionized or unionized ammonia. The ionized form, Ammonium (NH4), is present if the pH is below 7, and is not toxic to fish. The unionized form, Ammonia (NH3), is is present if the pH is 7 or above, and is highly toxic to fish. Any amount of unionized Ammonia (NH3) is dangerous, however once the levels reach 2 ppm, the fish are in grave danger. Ammonia usually begins rising by the third day after introducing fish.
2: During this stage Nitrosomonas bacteria oxidize the ammonia, thus eliminating it. However, the by-product of ammonia oxidation is nitrite, which is also highly toxic to fish. Nitrites levels as low as low as 1 mg/l can be lethal to some fish. Nitrite usually begins rising by the end of the first week after introducing fish.
3: In the last stage of the cycle, Nitrobacter bacteria convert the nitrites into nitrates. Nitrates are not highly toxic to fish in low to moderate levels. Routine partial water changes will keep the nitrate levels within the safe range. Established tanks should be tested for nitrates every few months to ensure that levels are not becoming extremely high.
Now that you know what is happening, what should you do? Simple steps such as testing and changing the water will help you manage the nitrogen cycle without losing your fish.
How To Avoid Disaster

The key for success is testing the water for ammonia and nitrites, and taking action quickly when problems occur. To aid in tracking the status of your aquarium, links to charts for logging your tests can be found under the charts section of this page. Each chart shows the danger zones and offers steps to reduce toxins before they result in loss of your fish.
Test for ammonia: Begin testing on day three after adding the fish, and continue every day until the ammonia begins to drop. After it begins to fall, continue testing every other day until the ammonia reaches zero. Using the chart provided, plot the ammonia levels. Should ammonia reach the danger zone, take steps as shown on the chart. If at any time fish show signs of distress, such as rapid breathing (gilling), clamped fins, erratic swimming, or hanging at the surface for air, take immediate action to lower the ammonia level.
Test for nitrites: Begin testing one week after adding the fish. Continue testing every second or third day, until it reaches zero. Using the chart provided, plot the nitrite levels and take steps as shown on the chart if nitrite reaches the danger zone. If at any time fish show signs of distress, such as rapid breathing or hanging near the surface seemingly gasping for air, test for nitrite. If levels are elevated perform an immediate 25-50% water change and test daily until levels drop.
What Not To Do

• Don't add more fish - wait until the cycle is completed.
• Don't change the filter media - the beneficial bacteria are growing there. Don't disturb them until they have become well established.
• Don't overfeed the fish - when in doubt underfeed your fish. Remember that anything going into the tank will produce wastes one way or another.
• Don't try to alter the pH - the beneficial bacteria can be affected by changes in pH. Unless there is a serious problem with the pH, leave it alone during the startup cycle process.

also, info on the ammonia poisons:

Ammonia Poisoning Written by Support Thursday, 27 March 2008

Ammonia Poisoning​

Ammonia poisoning is one of the biggest killers of aquarium fish. It occurs most often when a tank is newly set up. However, it can also occur in an established tank when too many new fish have been added at one time, when the filter fails due to power or mechanical failure, or if bacterial colonies die off due to the use of medications or sudden change in water conditions.
Ammonia poisoning can happen suddenly, or over a period of days. Initially the fish may be seen gasping at the surface for air. The gills will begin to turn red or lilac in color, and may appear to be bleeding. The fish will being to lose its appetite and become increasingly lethargic. In some cases fish may be observed laying at the bottom of the tank with clamped fins. Symptoms:

• Fish gasp for breath at the water surface
• Purple or red gills
• Fish is lethargic
• Loss of appetite
• Fish lays at the bottom of the tank
• Red streaking on the fins or body

As the damage from the ammonia poisoning continues, the tissues will be damaged as evidenced by red streaks or bloody patches that appear on the body and fins. Internal damage is occurring to the brain, organs, and central nervous system. The fish begins to hemorrhage internally and externally, and eventually dies.
Treatment:

• Lower pH below 7.0
• 25 - 50% water change
• Use chemical to neutralize ammonia
• Discontinue or reduce feeding

If the ammonia level rises above 1 ppm as measured by a standard test kit, begin treatment immediately. Lowering the pH of the water will provide immediate relief, as will a 50% water change (be sure to use water that is the same temperature as the aquarium). Several water changes within a short period of time may be required to drop the ammonia to below 1 ppm.
If the fish are in severe distress, the use of a chemical to neutralize the ammonia is recommended.
Feedings should be restricted so that additional waste is reduced. In cases of very high ammonia levels, feedings should be discontinued for several days. No new fish should be added until the tank until the ammonia and nitrite levels have fallen to zero.
Because ammonia toxicity is linked to the pH, testing of both ammonia and pH levels are critical. Ammonia becomes increasingly toxic as the pH rises above 7.0. Because there are so many variables, there is no magic number to watch for. However, there are general guidelines to follow.
At a level of level of 1 ppm or 1 mg/l, fish are under stress, even if they don't appear in acute distress. Levels even lower than that can be fatal if the fish are exposed continuously for several days. For that reason it is critical to continue daily testing and treatment until the ammonia drops to zero. When ammonia is elevated for a long period, it is not unusual to lose fish even after the ammonia levels start to drop.
Prevention:

• Stock new tanks slowly
• Feed sparingly and remove uneaten food
• Change water regularly
• Test water regularly to catch problems early

The key to avoiding fish death from ammonia poisoning is to avoid ammonia spikes in the first place. When starting a new tank, add only a couple of fish initially and do not add more until the tank is completely cycled. Even in an well established tank, only add a couple of new fish at a time and avoid overstocking.
Feed fish small quantities of foods, and remove any food not consumed in five minutes. Clean the tank weekly, taking care to remove an dead plants or other debris. Perform a partial water change at least every other week, more often in small heavily stocked tanks. Test the water for ammonia at least twice a month to detect problems before they become serious.
Anytime a fish appears to be ill, test for ammonia to rule out ammonia poisoning. If the filter stops, test for ammonia twenty-four hours later to ensure that the bacterial colonies that eliminate wastes were not affected.

 

Cool - good reading

 

Thanks guys there were a few things in both articals I did not know. This is a great thread for beginners

 

thanks feryman and solex, it was realy educational. my 1.2 tank is busy with a nitrate peak and now i know more or less how to combat the problem. i did a 30% water change and cleaned one of the filter media. i previously adjusted the ph level as it passed 7.5 but in future will leave them like they are till after the cycle finished. thanks again i realy appreciate it

 

So true what has been told here in this thread. Most, guess 98%, of Pet shops have no idea as to what has just been described here. This is something I go through with each new customer about to start out. The one thing I do find interesting is those that come in and tell me their friend told them to let the tank stand for a week or two to mature!!! A tank with water that is a week or two old that is what they have.
Organic Aqua produce the starter kit and maintenance kit and these do help immensely. I started a 120l tank, put in the Starter kit and dumped in 34 8-12cm Malawi's. A week later hardly any Ammonia and a further 10-12 days on hardly any Nitrites. Weekly water changes, via a gravel cleaner, also help immensely.
Nutrafin, Hagans the supplier, produce a booklet that explains this very well. When I have them I give them out and tell the customers to understand the Nitrogen cycle as they will enjoy the fish keeping a lot more as they will tend to have fewer losses of fish, especially during the first 2-6 weeks.
ENJOY!

 

Thanks folfs, both articles are very useful.... I have been on this forum for one week, and already have other people baffled with the cycles and terms.... I have a customer who bought a 4ft tank from an lps along with filters; lights; pumps and and and..... The next day the guy sold him fish to the value of about R600. Obvious result...... Dead fish and a very worried man.

I felt really bad for the guy, he was heartbroken at losing the fish (he is an animal lover of note). Then I explained what he should have done.... He said he would have to think about whether or not he would start again or sell the equipment...

 

That story is all too common in our hobby. In theory a tank can be sped cycled if you add the necessary bacteria either from a product available (eg Seachem's Stability/ Nutrifin's Cycle), or from an established tank... but even if the process is speeded up, I would still give it 3 days minimum.

 

Thats why I used all the advice I got from you guys... I am almost certain he will start fresh. And go slowly with it.

He is already talking about different species tanks it would be nice to have.

 

http://www.tropicalaquarium.co.za/showthread.php?t=2579

Some more Biological filtration advice from the Prof. Don't mind my stupid questions, I was also learning

 

LOL,reminds me when i took a big shortcut with my fish,i threw in 2x the reccomended(spelling) amount of bacteria and then added flakes as Zoom suggested.i waited 2 days for everything to settle then added all my fish at once,i thought that because i added 2x the reccomend bacteria the amonia spike would not be so large,it was 3 times smaller than that of my old tank but i would not recomend doing this since i don't know all the effects.

 

I find though that a lot of people who are not really serious about keeping fish, but want a tank, have an attitude of 'I don't want to have to do all that messing around', and just do their own thing!! But then when I try to tell them what might be the prob, they are even more dismissive and are like 'Well, I'm not that into fish keeping like you are!!' and ignore any advice I try to assist with!!

Drives me insane!!

One such case in point, some friends keep South American Tetras in a tank with coral and shells, and wonder why the fish are not lasting long!! So I tell them you need to either get fish that like higher pH (and give them some examples) or you need to get rid of the shells and coral, only to find that next time I see them they are still killing fish in the same tank with the same Coral and Shells!!

Sorry, didn't mean to go off on one, and I wasn't suggesting for a minute that this person you are speaking of is like this!! Just needed to get that off my chest I guess??

Cheers
G!

 

I agree totally Big G, some people seem to forget that a life is a life, no matter how small or insignificant it may seem....

I have also found that a lot of lps's only want to make a sale, not interested about anything else. I had a fight with the one in the case above earlier today. Guy said he only sells the stuff, it is not his problem what happens to it. Freeking pathetic if you ask me...

 

Hi all, It is an absolute shame that people are not given the correct advice when getting started. For a Tropical tank it is imperative to set the tank up, heater to get the water to correct temperature, then only go and buy your fish. Newcomers should also be given the advice of what to get started with. It does not help to sell the more fragile fish that require some sort of experience or greatly matured water.
The Bacteria cycle should settle within 4-6 weeksif all is well. The importance of 20% water changes, weekly, will also help to alleviate possble Ammonia, Nitrite amd Nitrate problems if they should occur. Removal and adding in new water helps dilute potential problems.
The Organic Aqua start up kit is an excellent product and should result in absolute minimal, if any, loss of fish within the first 4-6 weeks. i re-started a 100l Malawi tank, 34 fish at 6-8cm, and experienced no problems at all. This product releases, extremele quickly, the necessary bacteria.
A gravel cleaner is an also MUST as it does not help to take off the top water when all the muck, this is the stuff that has the pontential to cause major problems if left unattended, has settled on the bottom.
Richard, what fish did your friend get sold as a start up fish? I would really like to know!
I try annd relate to people what they are doing to their tank and what they should then do in their own home. If they only do a clean monthly then they should only clean their house, and bedding change, monthly! Those who unpack the tank sort of 3mthly get told to unpack their entire house onto the lawn, scrub out the house and wash what is on the lawn, and then to put it all back as it was! What is the harder work, a little each day/week or that I have described!
People must relise that the tank is the home for the fish. We don't live in a mess so don't allow your fish to live in a mess. I think the discerning pet shop owners need to say it as it is. So what if I loose a customer or two! I do not enjoy the stories of how all the fis died because of stupidity!

 

Hi All.

Thank you Solex69 & Ferryman for write up. It certainly helps me as well as others.

I have a 6foot tank. Been running for sometime with previous owner and then 2 weeks ago i bought it. I washed most of the items supplied. Filled in water let it cycle for a few days. I also added a blue liquid and some white powder supplied to me by the petshop. then after a few days i added the fish with the water supplied by the original owner. All is going well. The tank has a Tetra Tec 1200 external filter as well as airpumps.

What i would like to know:
a.How many days must one store the water , when doing the water changes , store the water in a container used only for the fishtank? As adding water directly from the tap is dangerous to the tank.
b.What must be added to the stored water?
c. The correct amount of water to change is +-20%?
d. Weekly or every two weeks or monthly?
e. Must i add more filtration?
f. What is the best/affordable water test kit to buy?

All help to my questions will be appreciated.

Thank you.

Viv.

 

Hi Viv

a. Usually 24 hours
b. Air stone and/or heater. Dechlor if you will
c. 20%-30% should be fine
d. Weekly. Every 2 weeks will do fine but then a greater water change
e. To speed up the process? The filters you use should remain used in that tank
f. Can't help you with that, sorry

Hope that helps. Answered to what i do. Correct me if I'm wrong please

 

Best test kits are expensive, affordable is useless test kits.

 

@Zoom

What price we looking at for decent test kit? Talking about the full range ones.

Thanks

 

I use API Master test kit, which is considered by many to be the most accurate in the range of "affordable" test kits. I think it goes for about R600.00

Does pH, (which isn't accurate by the way)
Ammonia,
Nitrites
and Nitrates.

Oh, and high pH.

 

Hi,

Thank you Troyfish & Zoom.

All your help and advise is much apreciated. This helps me to become a better tropical fishkeeper.

Is the Tetra Tec1200 external filter good for a 6 foot tank? Or must i buy an additional filter?

Zoom or others out there,
Considering all the money spent on buying good/decent equipment to make your tank run successfully, R600 for the test kit is not that bad at all. You did mention it is not accurate to ph levels. Can you recommend something even better?

BTW i have 4 Malawi cichlids in the tank.

Thank you all once again for the help and making TASA a great forum to be on.

Viv.