Cycling an Aquarium

[Bob2bob]

Thank you very much @Brew12 I plan to add some chaeto when i get the fish as well so I'd imagine that helps even more.

 

[Rich Cooper]

Unclear if my tank is cycled or not, could use some advice on what to do. I have a 75g with a 4ob sump and 50lbs of BRS reef saver dry rock as well as a bunch of marine pure blocks.

Starting my cycle:
I filled it with water and dumped a bottle of Bio-Spira on June 1st.

During cycle:
The only thing I've been doing is ghost feeding a pinch of cobalt flake food every day though from June 12-23rd I was out of town so the ghost feeding was put on hold in the middle of the month.

Water parameters: I couldn't test while I was away in the middle of the month.
Ammonia:
On 6/28 using the API kit i think I got a Ammonia reading of around .5
This morning on 7/1 it was significantly lower using the same test kit - maybe .1-.15

Nitrites:
Thoughout the month I've never really seen any noticeable Nitrites using the API kit. Perhaps the color had some shades of darker blue but was definitely always light blue/cyan

Nitrates:
Throughout the month I havn't really seen much Nitrates either. -- maybe around 3-5 right now. It's hard to tell with these API kits.

Algae:
I can see some kind of algae in the sump (display has been covered with towels) and it appears to really be getting more intense in color the last three or four days. It's on the white silicone I used to attach the baffles for the most part.

That seems like a quick cycle if it is completed already. If your cycle is done you should register some even minimal nitrates. did you ever register nitrites at all. All of my experiences cycling a tank i would have a small ammonia spike that would go away but then proceed to a small nitrite spike and then it would go away. Following the nitrite spike my ammonia and nitrite would always stay 0 after testing a few hours later and i would begin to have increasing nitrates until i exchanged new water. I also dosed with just ammonia and never did a food or cheap fish cycle.

 

[dimidragos]

I really don't know in what stage i'm with cycle my tank... I start 20 days before to cycle my 125g tank with 90lbs Real Reef Rock and 70 lbs live sand. Salinity 1.025, Ph 8.2, temp80F. I start without any media in sump, only with a ClariSea SK5000 filter and a return pump. For aeration and water circulation i was use in beginning two Tunze 6095. I add Microbact7 and Stability in begin every day. Artificial light off. Few days ammonia, nitrite, nitrate 000 value. After around one week i add one table shrimp around 2.5-3 inch. Again nothing, all tested value 0000. I start ghost feeding also, just a bit. 5 days before, 15 days after i start i see first change nitrate show very low value around 0,2-0.5. I stop ghost feeding to see what happend. After two days nitrite was 0,025-0.05 and nitrate 5, next day nitrite 0,1 and nitrate 10, today nitrite 0,1-0,2 and nitrate 25-30. I understand that nitrate rice up during the nitrogen cycle and i beleive it's normal. What i don't understand it's why my system can't deal with this amount of nitrite witch is growing up each day... I shuld perform a water change soon?? Yesterday i add 2 liter of Aqua Forest Life BioFil and today 2 liter with Seachem Matrix, i hope this will help me...The water don't smell, it's crystal clear and there it's not any sign of algae

 

[dimidragos]

I use the light only for photo and it's a temporary light also, when the tank will be ready i will use a Orphek V4.

 

[Brew12]

What i don't understand it's why my system can't deal with this amount of nitrite witch is growing up each day

The bacteria that process nitrite tend to reproduce more slowly than the ones that process ammonia. They also don't store as well when bottled. What you are seeing is very normal. Fortunately, nitrite isn't a problem for marine fish. The chlorides in the water prevent the nitrite from being absorbed by the fish.

when the tank will be ready i will use a Orphek V4

I feel like you are ready now. Personally, I like a little algae in a new system prior to adding fish and often add macro algae prior to the first fish. Algae process ammonia directly faster than the bacteria and help keep the fish safer in the event there is an ammonia spike.

 

[dimidragos]

The bacteria that process nitrite tend to reproduce more slowly than the ones that process ammonia. They also don't store as well when bottled. What you are seeing is very normal. Fortunately, nitrite isn't a problem for marine fish. The chlorides in the water prevent the nitrite from being absorbed by the fish.


I feel like you are ready now. Personally, I like a little algae in a new system prior to adding fish and often add macro algae prior to the first fish. Algae process ammonia directly faster than the bacteria and help keep the fish safer in the event there is an ammonia spike.

My problem it’s why the nitrit still rise when i add soo less food. But its clear that the bacteria who processes nitrit it’s not enough mature. I was thinking to ask if it’s something to do but I think it’s only a matter of time....hopefully.
In one week I plan to add some amonia chloride to have a better view of the process.
About algae I was planning clear to build a refugium but I change my mind because of restricted space. I will ad a 4 liter algae reactors in max two weeks and I will start to add fish one week after if everything goes well. I was thinking to wait with the algae reactor to see how good perform my system in matter of stripping nutrients. I’m not so pleased until now...but I hope for better.

 

[Brew12]

My problem it’s why the nitrit still rise when i add soo less food.

I would suspect that the food you have previously added is continuing to break down and add ammonia into the water.

 

[lapin]

2 x post

 

[lapin]

I agree with the above statement. I would suspect that the food you have previously added is continuing to break down and add ammonia into the water which is being converted to nitrite then nitrate.
I would do a large water change to bring down your nitrates. I don't think you need to add any ammonia. It will just make your nitrate rise. Then you can add 1 or 2 small fish or corals. Wait a few weeks before you add a clean up crew. Get that scrubber going and you are on your way

 

[dimidragos]

I agree with the above statement. I would suspect that the food you have previously added is continuing to break down and add ammonia into the water which is being converted to nitrite then nitrate.
I would do a large water change to bring down your nitrates. I don't think you need to add any ammonia. It will just make your nitrate rise. Then you can add 1 or 2 small fish or corals. Wait a few weeks before you add a clean up crew. Get that scrubber going and you are on your way

Hello, Lapin thanks for your advice. I don't think i will make a water change now because i believe that the nitrate level its normal in this momment. I hope i will get better nitrate value later with WC and algae reactor in function. I'm still worry about the nitrite level witch it's still 0,1-0,2 almost one week after i stop ghost feeding. Of course i'm agree with @Brew12, it's a big chance that the food and shrimp added previously continuing to break down. I want to wait and see the nitrite 0 and then to start to deal with NO3. That's my idea and i hope i don't make any mistake... if you or someone think it's a mistake please let me know

 

[BedrockIOMC]

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.

I love this info, thank you so much. I learnt a lot reading this very helpful.[emoji3] [emoji3] [emoji3]

 

[Brew12]

Hello, Lapin thanks for your advice. I don't think i will make a water change now because i believe that the nitrate level its normal in this momment. I hope i will get better nitrate value later with WC and algae reactor in function. I'm still worry about the nitrite level witch it's still 0,1-0,2 almost one week after i stop ghost feeding. Of course i'm agree with @Brew12, it's a big chance that the food and shrimp added previously continuing to break down. I want to wait and see the nitrite 0 and then to start to deal with NO3. That's my idea and i hope i don't make any mistake... if you or someone think it's a mistake please let me know

I think you are on the right track. I also agree with not doing a water change yet. Don't be surprised if your nitrate reading drops when your nitrite goes to 0ppm. Nitrate tests work by converting nitrate to nitrite and then measuring it. Any nitrite will cause nitrates to read higher than they actually are.

 

[Brew12]

I love this info, thank you so much. I learnt a lot reading this very helpful.[emoji3] [emoji3] [emoji3]

Thanks, glad you found it useful!

 

[BedrockIOMC]

Thank you! I wanted this to be the article with the information I would have wanted when I set up my tank.

Now if only I could figure out how to shrink the photos to a more reasonable size. :confused:


Glad you like it. I could have written pages more. Actually, I did write more. A lot more. Especially regarding the use of bottled bacteria and skip cycling. It just got to be too much with all of the different rabbit holes you can go down. I wanted to keep this a bit more simple in a way that wouldn't overwhelm a new hobbyist.

Where can I find the other that you wrote about the bottle and skip cycle? I'd like to read that.

 

[Brew12]

Where can I find the other that you wrote about the bottle and skip cycle? I'd like to read that.

Unfortunately, I deleted it all. When I started editing this I decided to cut much of that out.

Skip cycling is easy to do. I recommend Biospira or Dr Tims One and Only, but many other products work. Get your tank set up and rockscape where you want it. Get your water up to temp with some flow. Add the bottle of bacteria and some pure ammonia or ammonia chloride to achieve 2ppm. Odds are your tank will be ready in a day or two.

 

[TheEngineer]

How have I missed this article? Wonderful stuff!

Since I’m on my reboot journey, I’ll throw in my own question...My tank is using all live rock that’s from my previous build. The rock has been cooking in saltwater for 4 months (my stand build took longer than expected). It should be very much alive, right? The magic question is whether or not I should wait before moving my fish (3 total) and corals over from their holding tanks?

 

[Brew12]

How have I missed this article? Wonderful stuff!

Since I’m on my reboot journey, I’ll throw in my own question...My tank is using all live rock that’s from my previous build. The rock has been cooking in saltwater for 4 months (my stand build took longer than expected). It should be very much alive, right? The magic question is whether or not I should wait before moving my fish (3 total) and corals over from their holding tanks?

Glad you liked it!

Did you keep the rock heated and with flow? If so, it should be just fine.

 

[lapin]

Should be very alive unless you acid and beached everything off it. Even then 4 months should be enoughttime for bacteria to grow back. A test of your numbers will help decide that.

 

[TheEngineer]

Flow, yes. Heat, no. It sat in my office in a tub. House is usually around 75F so it was sorta heated :)

I don’t believe in acid or bleach washing. I paid good money for this rock I don’t wind to wind up with less rock :) haha

 

[Brew12]

Flow, yes. Heat, no. It sat in my office in a tub. House is usually around 75F so it was sorta heated :)

I don’t believe in acid or bleach washing. I paid good money for this rock I don’t wind to wind up with less rock :) haha

Yup, shouldn't be a problem! I would only worry if you had let it freeze.