Cycling an Aquarium

[Lasse]

Evening #reefsquad,

Is my cycle complete? I'm not sure,
Parameters are:
Ammomia 0
Nitrate 2.5
Nitrite 22
Phosphates.07

No fish, no corals yet. Only ghost feeding. I have 10 trocus snail and about 15 hermits in display currently.

No cloudy water, just diatom starting to cover rock and substrate

You think I should get some chaeto and start that? Should I dose ammonia to check?

You cycle has stall before the second step (NO2-NO3) Your high reading of NO3 is caused of your NO2 readings - it is false.

DO NOT add any more ammonia - it will do the situation worse. The step NH3/NH4 works well - you need to have the second step to work. Stop ghost feeding - take away all excess food from the gravel. In order to have the second step to work in short time you probably need to add nitrifying bacteria from a bottle or from another source. Add every day till you read 0 or very close to 0 of NO2. Another source could be unrinsed gravel from another working aquarium, squeeze a working foam filter and dilute the dirt in some water – keep in refrigerator – and dose a “dash” every day until you read zero NO2 . Another method is to take a handful of unfertilized soil in a litre of water, filtrate through a coffee filter, store the filtrate in the refrigerator and “dash” in some every day until you read 0 NO2


Sincerely Lasse

 

[TK_KW]

Evening @Lasse @Crabs McJones,

Tank cycle is on day 36 from when i added first Seed. I stopped ghost feeding yesterday. I changed filter socks that where brown(only two weeks old, But some pellets in them). I have added a TON of nitrifiying bactira to date. First added Seed as recommended from bottle, didnt really notice anything with parameters. But I have since added couple botttles of turbofritz 900. I actually added one about four days ago. I do have a all in one dr tims on had and couple more of bio spira if needed.

So am i gathering i should be testing Nitrite daily and get it down to zero? Then i can proceed to turn on skimmer and UV. Bare with me for any stupid questions as this is my first cycle. But ive built this system with every possible forsight I could think of to acheive sucsess.

 

[FREAKINRICAN69]

Cycling a new aquarium.​

One of the earliest topics a new aquarium hobbyist needs to learn is how to properly cycle their aquarium. There is a ton of information on this process and many different methods on how to accomplish it. There are many different chemical and biological cycles our tank goes through as it matures but this addresses the one most commonly discussed.


What is cycling?

The term cycling comes from the process known as the “Nitrogen Cycle”. When a plant or animal decays, or an animal expels waste, nitrogen is released. In our aquariums we initially see this as ammonia. Bacteria converts the ammonia to nitrite and then to nitrate. When we have enough bacteria to quickly convert ammonia to nitrate, we say that our tank has cycled. This is deceiving because the process doesn’t stop at this point and it is never complete. For this reason we need to think of this as establishing a large enough bacteria population to support fish, not completing a cycle.


Ammonia is a waste product of a fish’s cellular activity which is expelled through their gills. If the ammonia in the water is higher than in their blood it cannot be released and builds up in the fish causing cell damage. Nitrosomonas bacteria use ammonia as food and convert it to nitrite.

Nitrite is also harmful to fish. In a fish, nitrites hinder the ability of its blood to carry oxygen. Nitrites are a serious issue in fresh water systems. The same receptors in a fish that would absorb nitrites have a higher affinity for chlorides. The chlorides in saltwater block nitrites from being absorbed and protects the fish in marine systems. We rely on a different species of bacteria, Nitrobacter, to convert nitrite to nitrate.

Nitrates are relatively harmless for fish unless it reaches very high levels. Nitrates leaves our tank in any number of ways. We get rid of it via water changes. Algae and some corals can consume it as food.

The last part of the cycle is when nitrate is converted to nitrogen gas. This is done by anaerobic bacteria inside porous rock or within deep sand beds. Not every aquarium has the necessary conditions for this to occur

What conditions do I need for the cycle to occur?

To provide a good environment for the bacteria, we only need to make sure they are wet, oxygenated, and the pH is between 6.5 and 8.5. They will grow best at a temperature close to where we keep our tanks however they will still survive and reproduce at temperatures between 45F and 100F. We also want to monitor ammonia during this process. If ammonia gets over 5ppm it can slow down the rate bacteria reproduce. Above 10ppm it can stall the cycle.


How does rock affect the cycle?

The rock in a marine tank is the core of its filtration system. We use porous rock to provide as much surface area as possible for bacteria to grow on. The water flowing around the rock brings the ammonia and nitrites to the bacteria. If the rock is large enough it may have anaerobic bacteria deep within it that can convert the nitrates to nitrogen gas.

There are many types of rock that are available in our hobby. I won’t get into all of the different types but I do want to address how dry and live rock impacts the cycle

Dry rock is just that. It is rock that has been dried out and has nothing alive on it. Dry rock can be “clean” where it is considered safe to put directly into an aquarium. If it is not clean it will need to be cured prior to use. Either way, it will not contain nitrifying bacteria. This isn’t a problem as nitrifying bacteria are everywhere and it would be impossible to keep them out of our aquarium even if we wanted to.

Live rock is rock that does have living bacteria on it. The main reason to use live rock is to speed up the cycling process. Just like with dry rock, not all live rock is ready to put immediately in an aquarium. For simplicity I am going to put live rock in 2 broad categories. If your live rock came directly out of a marine system and is kept submerged in quality water during transport you can put it directly into your tank. If the rock was exposed to air or shipped damp then it needs to be cured prior to use. The bacteria on this rock will be fine but other living things may have died and should be removed prior to putting it in your tank.

How do I feed the bacteria?

There are many different takes on this and it is largely a matter of opinion. So here are the most common ways from worst to best in my opinion.

Adding a fish – while it will work as an ammonia source, why would you make a fish suffer in an environment in which it can’t properly shed its toxins?

Ghost feeding – When you add food to the tank you are adding much more than just what breaks down to ammonia. While none of it will be a problem, other than possibly algae, this is an uncontrolled process.

Adding a shrimp – The shrimp will decay and create ammonia, but again, this is an uncontrolled process. How much ammonia will this add and how quickly? I don’t know.

Dosing pure ammonia – This is the only method I will ever use in the future. You can measure exactly how much you need to add to achieve a specific level of ammonia. You can measure just how quickly your bacteria consume it to judge the health of your bacteria population.

How do I recommend doing it?

I’m glad you asked! I’ll start from the point where the tank is set up, filled, has flow, and temperature is in the normal range. It doesn’t matter if you used live or dry rock.

I will either use pure ammonia or ammonium chloride to raise the total ammonia to 2ppm. I will test for ammonia, nitrites, and nitrates daily until ammonia is near 0ppm. I will then dose it back up to 2ppm while continuing daily tests. I will repeat this process in a smaller tank until ammonia goes from 2ppm to 0ppm within 24 hours. In tanks that are 90g+ that will be stocked slowly I will only dose to 1ppm ammonia after the initial dose and consider it cycled when it drops from 1ppm to 0ppm in 24 hours. This is to limit nitrates in larger tanks. Keep in mind that a 120g system that drops 1ppm in a day can support more fish than a 40g tank that drops 2ppm in a day.

But I still have questions!

Ok, let me see if I can answer some of the more common ones.


If nitrifying bacteria are everywhere, why are “bacteria in a bottle” products so popular?

Nitrifying bacteria are everywhere so that isn’t the problem. Some bacteria can double their population in 20 minutes. Luck would have it that these tend to be the more poisonous kind. Nitrifying bacteria are relatively slow reproducers and it takes between 8 and 24 hours for them to double their population. If you start with dry rocks it can take a month or two to produce enough bacteria to support even a few small fish. Using bacteria in a bottle instantly provides a larger source of bacteria to speed up the front end of this process.

My cycle went fine for 3 weeks but now it stalled, what happened?

It could be any number of things. Did you let your ammonia go to high? Do you have a pH issue?

Your nitrifying bacteria may be being outcompeted for resources with other bacteria and/or algae. They may process ammonia fine at first but they will eventually go dormant. When this happens, your cycle will stall until a more marine friendly bacterium reproduces enough to begin the cycling process again. Bacteria in your tank are in constant competition for food. Eventually the one best suited to your specific system will thrive.


Can I vacuum out too much bacteria by cleaning? Will cleaning my sand bed cause my tank to cycle?

No, you cannot hurt your bacteria population by routine vacuuming or water changes. These bacteria are very difficult to remove from solid surfaces and would be difficult to remove even with scrubbing.

If your sand bed is very dirty you may cause an ammonia spike that is larger than your current bacteria population can handle but you haven’t done any harm to your bacteria population.

Can I use old tank water to cut back on my new tanks cycle time?

You can, but it won’t help much. The majority of the bacteria is going to be growing on hard surfaces, not floating in the water. There will be some, however, so you will likely introduce a strain of bacteria into your new tank that will eventually work very well.

I never measured any nitrite during my cycle, is this a problem?

No, odds are this is not a problem. It is possible that you had a larger initial population of Nitrobacter bacteria (nitrite eaters) compared to Nitrosomonas bacteria (ammonia eaters). In this case the nitrite was processed to nitrate almost as soon as it was produced.

Another possibility is that you have a large population of Nitrospira bacteria. These bacteria convert ammonia into nitrite and then to nitrate within the same cell structure so the nitrite is never released into the water to be measured.

My tank has been empty for 6 months, did my bacteria starve?

No. It is almost impossible to starve bacteria. They will adjust their metabolism and reproduction rates based on the food supply. As the amount of available food goes down, they will process it slower and reproduce less. If they go without food long enough they will go into a cystic stage (typically around a year without food). Once food is available again it will take longer for them to recover from this stage but they are still viable.

This does not mean that your tank is ready for fish after sitting dormant for up to a year. Bacteria is part of the food chain and is consumed by many different organisms. Just because your bacteria didn’t starve doesn’t mean it didn’t get eaten or is still viable. Every aquarium will respond differently based on its unique biology.

Why can I add more fish to an older aquarium faster than a new aquarium?

Let’s say you have 2 identical aquariums set up one year apart. They both have the exact same number and size of fish and both have 0 ppm ammonia and nitrite. They must have the same amount of bacteria, right? Well, no. The older tank will have a larger population of bacteria that is processing ammonia at a slower rate. The younger tank will have a smaller population of bacteria with faster metabolisms. If you add new fish to the younger tank you need to wait for the population to increase which can take days. In an older aquarium, the bacteria only need to become more active which can happen in a matter of hours.

Awesome article...

 

[Brew12]

Evening @Lasse @Crabs McJones,

Tank cycle is on day 36 from when i added first Seed. I stopped ghost feeding yesterday. I changed filter socks that where brown(only two weeks old, But some pellets in them). I have added a TON of nitrifiying bactira to date. First added Seed as recommended from bottle, didnt really notice anything with parameters. But I have since added couple botttles of turbofritz 900. I actually added one about four days ago. I do have a all in one dr tims on had and couple more of bio spira if needed.

So am i gathering i should be testing Nitrite daily and get it down to zero? Then i can proceed to turn on skimmer and UV. Bare with me for any stupid questions as this is my first cycle. But ive built this system with every possible forsight I could think of to acheive sucsess.

It sounds like you may have added so much food that you are replicating high stocking levels in a new tank. At this point I would consider vacuuming or stirring the gravel and getting as much decaying matter into the filter socks and change them out every 2 or 3 days. Your nitrite should go to 0 fairly quickly if you can get the tank cleaner.

I know I'm not on the normal side of this, but I like cycling with a light on. I like algae. Algae will help process ammonia and support the nitrifying bacteria. I prefer to try and grow algae and add a clean up crew earlier in the process instead of later.

 

[TK_KW]

It sounds like you may have added so much food that you are replicating high stocking levels in a new tank. At this point I would consider vacuuming or stirring the gravel and getting as much decaying matter into the filter socks and change them out every 2 or 3 days. Your nitrite should go to 0 fairly quickly if you can get the tank cleaner.

I know I'm not on the normal side of this, but I like cycling with a light on. I like algae. Algae will help process ammonia and support the nitrifying bacteria. I prefer to try and grow algae and add a clean up crew earlier in the process instead of later.

Sorry one thing I did forget to mention. From day one lights were off. I did however turn them on for about 6-7 consecutive days in the last week. Ive since turned them back off. Does this change your thought? I had been concerned because my tank was clean (and i had added some CUC maybe to ealry) I was looking to possibly create diatom or algea for them and to help the process. Not sure if i had the right idea behind it. But thats what ive done. Let me know how you guys think I should proceed. Cheers

 

[Brew12]

Sorry one thing I did forget to mention. From day one lights were off. I did however turn them on for about 6-7 consecutive days in the last week. Ive since turned them back off. Does this change your thought? I had been concerned because my tank was clean (and i had added some CUC maybe to ealry) I was looking to possibly create diatom or algea for them and to help the process. Not sure if i had the right idea behind it. But thats what ive done. Let me know how you guys think I should proceed. Cheers

If you've added a CuC then you should run with the lights on. No harm done but you need to have food growing in there for them to eat.

 

[Lasse]

I would turn my skimmer on because it will help with the oxygen level in the system. My experiences say that the first step NH3/NH4 -> NO2 can happen with as low O2 levels as 3 ppm but the second step needs O2 levels above 5 ppm.

If you have both add ammonia and ghost feeding you probably will have a lot of decaying bacteria that consume oxygen. These bacteria will also live on surface and they will compete out the nitrifying bacteria (especially the second stage bacteria NO2 -> NO3) because of faster growth. I tend to agree with what Brew12 write in this case.

At this point I would consider vacuuming or stirring the gravel and getting as much decaying matter into the filter socks and change them out every 2 or 3 days.

Normally – do not touch the sand bed is golden words from me – but in this case I agree with Brew12

If you have an internal foam filter around – you can use that in order to have the NO2 go to zero.

I also agree with turning the light on – if you can for the whole photo period you plan to have but with lower intensity in the start.

I also like the nitrification article, except for the part not to use fish as an ammonium source. Done in the right way, the fish will not feel that you are cycling the aquarium – you will not create huge concentrations of NH3/NH4 in that case. – see my article about 15 steps

Sincerely Lasse

 

[TK_KW]

I would turn my skimmer on because it will help with the oxygen level in the system. My experiences say that the first step NH3/NH4 -> NO2 can happen with as low O2 levels as 3 ppm but the second step needs O2 levels above 5 ppm.

If you have both add ammonia and ghost feeding you probably will have a lot of decaying bacteria that consume oxygen. These bacteria will also live on surface and they will compete out the nitrifying bacteria (especially the second stage bacteria NO2 -> NO3) because of faster growth. I tend to agree with what Brew12 write in this case.



Normally – do not touch the sand bed is golden words from me – but in this case I agree with Brew12

If you have an internal foam filter around – you can use that in order to have the NO2 go to zero.

I also agree with turning the light on – if you can for the whole photo period you plan to have but with lower intensity in the start.

I also like the nitrification article, except for the part not to use fish as an ammonium source. Done in the right way, the fish will not feel that you are cycling the aquarium – you will not create huge concentrations of NH3/NH4 in that case. – see my article about 15 steps

Sincerely Lasse

Morning,

Ok so is this my action plan,

-Test no2 daily( until zero is meet)
-Stir up gravel, or possibly vacuum with small water change
-Keep lights on with lower levels
-Turn on the skimmer
-Add more nitrifing bacteria

Does this sound about right?

@Lasse sorry what do you mean a internal foam filter? Something i get and put in my sump?

I'll most def take a read through your article aswell. Thanks again @Brew12 and @Lasse for you help.

 

[Lasse]

sorry what do you mean a internal foam filter? Something i get and put in my sump?

I mean something like this type from Eheim or this type from Hagen. I use foam filter - but I think "sponge" filter is mor accurate. As fast flow through the sponge as possible. I always have on DIY in my sump.

Sincerely Lasse

 

[Brew12]

Morning,

Ok so is this my action plan,

-Test no2 daily( until zero is meet)
-Stir up gravel, or possibly vacuum with small water change
-Keep lights on with lower levels
-Turn on the skimmer
-Add more nitrifing bacteria

Does this sound about right?

@Lasse sorry what do you mean a internal foam filter? Something i get and put in my sump?

I'll most def take a read through your article aswell. Thanks again @Brew12 and @Lasse for you help.

I don't think I would add more nitrifying bacteria but otherwise I think this looks like a good plan. It won't hurt to add more but at this point I also don't think it will help much. When people ghost feed a tank they may add a small pinch of food weekly. I feel that once you get some excess decaying food out of your system you will be in good shape without adding more bacteria.

 

[Jeffrey1305]

Hi I’m cycling tank with af bio s it’s been a week and I have raw shrimp in there as well not seeing any spike in ammonia and just a bit of nitrate is it because of the bacteria ?

 

[Brew12]

Hi I’m cycling tank with af bio s it’s been a week and I have raw shrimp in there as well not seeing any spike in ammonia and just a bit of nitrate is it because of the bacteria ?

Sounds like it. The bacteria should be converting the ammonia to nitrate before you can get a reading on it. That is a good sign.

 

[Jeffrey1305]

Sounds like it. The bacteria should be converting the ammonia to nitrate before you can get a reading on it. That is a good sign.

Do you think it’s ok if I add fish to the tank once the suggested two weeks of adding bacteria is done ? Or should I wait some time without adding bacteria and c what’s happening ?

 

[Brew12]

Do you think it’s ok if I add fish to the tank once the suggested two weeks of adding bacteria is done ? Or should I wait some time without adding bacteria and c what’s happening ?

As long as you see no sign of ammonia or nitrite along with increasing nitrate the entire time I think you will be fine to add a small fish or two at the end of the process.

 

[BeejReef]

Congrats on being really patient and disciplined. 36 days with all you've done to augment, chances are you're more than cycled. Verify and tidy up ofc, but you've got to be near ready.
A chaeto fuge was a great help to me in exporting a lot of the nastiness.

I'd personally put in one or two cheap frags so you have an excuse to run the lights and fire them up! Watching the CUC, and cursing at them for avoiding the clumpy stuff you bought them to eat, is one of the things I've enjoyed most in my young tank.

 

[dennism]

Sounds like it. The bacteria should be converting the ammonia to nitrate before you can get a reading on it. That is a good sign.

I am getting the same I've been testing daily and after a week of startup using nitrifying bacteria and live sand my highest ammonia test has been. 025 ppm. I did put a dead shrimp in the tank on day 3. Now it looks cooked but the temp is 75degrees

 

[Joe del Rey]

Hi! Your article was very informative.
Do you have another article about using bacteria in a bottle?
I am about to use one soon (API Quick Start) so I wanna learn something more.

 

[BST96]

Hi all hoping to get some guidence from those more experienced than I. I started cycling a new 50G tank two weeks ago yesterday. I have the Carib Sea live sand and about 35 lbs of their life rock. Tested for the first time and below are the results:

Ammonia: 0.25 PPM kind seemed on the edge between this and 0PPM
Nitrite: 0PPM
Nitrate: 0PPM
Ph: 8

I am trying to determine if the cycle is just beggining or has completed? Couldnt seem to find any info on low ammonia and zero nitrite & nitrate. No lights have been ran, only skimmer and return pumps. And I used the API kits if that makes any difference.

Any guidence would be much appreciated.

Thanks,
Ben

 

[Brew12]

Hi all hoping to get some guidence from those more experienced than I. I started cycling a new 50G tank two weeks ago yesterday. I have the Carib Sea live sand and about 35 lbs of their life rock. Tested for the first time and below are the results:

Ammonia: 0.25 PPM kind seemed on the edge between this and 0PPM
Nitrite: 0PPM
Nitrate: 0PPM
Ph: 8

I am trying to determine if the cycle is just beggining or has completed? Couldnt seem to find any info on low ammonia and zero nitrite & nitrate. No lights have been ran, only skimmer and return pumps. And I used the API kits if that makes any difference.

Any guidence would be much appreciated.

Thanks,
Ben

What did you add for an ammonia source?

 

[Brew12]

Hi! Your article was very informative.
Do you have another article about using bacteria in a bottle?
I am about to use one soon (API Quick Start) so I wanna learn something more.

I don't, but if the bottled bacteria works correctly your system should process small amounts of ammonia to nitrate almost immediately with no sign of a cycle.