The Cycling Process

 

 

Now let’s discuss the cycling process! This is usually where I lose the attention of most beginners. When trying to explain the cycling process, I’m usually met by confusion as though I’m speaking Charlie Brown to them. I will try to make this as quick and painless as possible, while still helping you understand what this dreaded “cycle” really is. It’s not that bad, I promise!

What is the Nitrogen Cycle?

When you hear people discuss “cycling” a new tank, we are talking about the nitrogen cycle. The nitrogen cycle is the process of creating beneficial bacteria that will detoxify waste that would otherwise be harmful. Sound confusing? It isn’t, bear with me. Your fish don’t have the benefit of a toilet or sink to get rid of their waste, instead they have to sit in an aquarium where this waste will build up. While filtration can remove some of these floating particles, where do you think this waste goes? It does not magically disappear and in fact, sits in your filter and will continue to decompose. To try to put it into perspective for you, it would kind of be like having a bucket as a toilet and a sink that doesn’t drain and nowhere to dispose of the waste. Luckily the nitrogen cycle breaks down those toxins into something much more safe.

How it works

So without getting too scientific and losing you; here’s how it works in an aquarium. Fish produce ammonia (NH3, NH4) which is toxic to fish; but as these beneficial bacteria colonies start to form, ammonia is converted into nitrite (NO2) which is still harmful, but less toxic. The nitrites then convert into the less harmful nitrates (NO3) which is our ultimate goal. When initially starting a tank these bacteria colonies haven’t formed yet, therefore you will see an immediate spike in the dangerous ammonia. Once these bacteria colonies have established and your tank is finished cycling, ammonia and nitrites should not be present and you will be left with the less harmful nitrates. Keep in mind that even though nitrates are the least harmful, they should still be kept under 40ppm after your cycle and ideally under 20ppm after your tank has become stable with it’s colonies after a few months.

So where do these colonies live? They live in your water, your decorations, in your substrate, and most importantly; in your filter. Your filter has many uses and while you may think that “cleaning” your tank is it’s most important function, it’s actually home to the majority of your colony.

 

Let’s get started

There are two different options to cycling a tank; with fish and without fish.  The key factor is to have a source of ammonia, which can come from fish waste, fish food, decaying shrimp, or even pure ammonia. Here is an example of what the nitrogen cycle will look like. Keep in mind that every tank is different and will cycle at a different speed depending on many factors.

With fish cycling

Many of us have unknowingly cycled a tank with fish over the years when information wasn’t as readily available.  This option seems to be the more desired choice of beginners since many people are eager to add fish right away. As you become more experienced, you’ll start to realize the importance of having patience. You’ll save yourself money and frustration if you simply do it right the first time.  Cycling your tank with fish isn’t necessarily a bad choice, but keep in mind that you will be adding more factors into the equation.

Pros:

• It can feel like the easier option, and sometimes it can be.
• Immediate satisfaction having a tank with fish in it.

Cons:

• Higher risk of mortality in fish.
• Frequent water changes are a must to reduce the dangerous levels of ammonia and nitrite.
• Secondary infections could occur in fish as they become stressed. You may be tempted to want to treat these infections with medications, but by doing so can be counterproductive. Many medications will cause your colonies to die off and “crash” the system, which would mean starting the cycle over.
• Will not have the option to turn up the heat to a higher setting as it can be harmful for fish. Turning the heat up will be discussed in the cycling tips section.

How to do a fish-in cycle; first I want to stress to you that even though you plan to start with fish, it is best to only start with a small amount. By only having a small amount of fish producing a small amount of waste, the spikes should not be so dramatic. By stocking lightly, you give yourself a nice cushion with the amount of dangerous spikes that will occur in your tank.

A rule of thumb is one 1″ fish fish per 10 gallons. That does NOT mean 1″ per 10 gallon. Therefore you would want five 1″ fish for a 50 gallon tank, not one 5″ fish. It is somewhat possible to try this method, but keep in mind that some larger fish tend to have higher bioloads (waste) and can quickly become out of hand. During this time you will need to closely monitor your water quality. This may mean having to do small water changes multiple times per week in order to keep the toxicity down for the fish.

As shown above; the first thing present in your tank will be ammonia which will be started the moment your fish are added to the tank. Be aware that even small traces of ammonia can be toxic to fish so it’s important to keep ammonia below 2ppm and nitrite below 1ppm. You can keep these levels down by doing small 10%-25% water changes until they are at a safer level and also be careful to not overfeed, especially during this time. Products such as Prime or Amquel Plus are highly recommended as they help neutralize harmful ammonia and nitrites. Do not use more than once every 24 hours though. Ammonia will start to spike typically after a few days, keeping in mind that every tank’s experience will vary. As discussed before ammonia will be the first to spike, and as nitrites become present and start to spike, the ammonia will start to fall. Nitrates will slowly become present and your cycle will be complete once you have a reading of 0ppm for both ammonia and nitrites. With fish present in the tank, it’s very important that you closely monitor your readings to ensure that your spikes are not too extreme. This may require you to do a water change every other day.

Once your tank is at 0 ppm for both ammonia and nitrite, you will be safe to add additional fish. Please keep in mind that you should only add a small amount of fish at a time; the more moderate you can be, the better. Typically if you only add a small amount of fish at a time you will not run the risk of cycling your tank terribly as your colonies scramble to adjust to the increase in ammonia. Please continue to monitor your water though and only add fish once the ammonia and nitrite aren’t present.

For extra tips on how to cycle you tank, click here

Without Fish

While it may not be as gratifying to do a fishless cycle, the amount of stress you will save not worrying about losing fish will be invaluable. Here are the pros and cons with doing a fishless cycle;

Pros:

• Water changes aren’t as frequent as they would be with fish.
• No worries in fish losses during the cycling process.
• Less factors to worry about leaving more time to simply focus on the cycle, no need to worry about fish health or spikes being too extreme.

Cons:

• No immediate satisfaction getting fish.
• Having to manually add a source of ammonia is replace of live fish.
• Keeping the excited children (or fiance in my case) at bay as they grow more impatient to add fish.
• You, yourself, may start to become more impatient to add fish!

There are a couple different options when doing a fishless cycle;

1. Adding pure ammonia/janitorial ammonia
2. Adding fish food
3. Adding raw shrimp

Adding pure ammonia

While this method may seem complicated and deter many beginners, it doesn’t need to be difficult and can actually be quite simple. It is be the best way to cycle your tank because not only will no fish be involved that could get stressed, but this method is also the safest if done correctly. Other methods could smell, look unpleasing, and introduce mold, this method will not and is considered clean.

Things you will need

• Pure ammonia/Janitorial Ammonia
• Syringe
• Test Kit
• Calculator

I am going to make it as simple as possible for you and include a volume calculator to show you exactly how much ammonia you will need to add. You will want to keep your ammonia levels between 2ppm-4ppm. I recommend keeping your ammonia levels around 2ppm or slightly higher,  unless you plan to stock a lot of fish or start with larger fish in which I would recommend keeping your levels closer to 4ppm. Keep in mind if you do decide to keep your ammonia at 4ppm it may take longer to cycle. With the calculator find out the exact amount of ammonia you will need to add and begin dosing daily. You will initially see the presence of ammonia which will start to spike. During this time the presence of nitrite will slowly start to occur; and as the nitrites spike, the ammonia will start to fall. Once nitrates have started to show, the cycle will be just about finished; and once nitrites and ammonia show a reading of 0ppm, the cycle will be finished. Below is a graph showing you a basic idea what you should expect to see with your readings.

As shown, once nitrite and ammonia have a reading of 0ppm, the cycle will be complete and ready for fish. Continue to add ammonia until you are ready to add fish to keep your new bacteria colonies stable. Once you are ready, do a large enough water change to get a reading of 40ppm nitrates. DO NOT VACUUM GRAVEL OR CLEAN FILTER! You water change should only be the removal of water, nothing more.

For more tips on how to cycle your tank click here

Adding Fish Food

Things you will need:

• Fish food
• Test Kit
• Gravel Vacuum

This method is done by adding in fish food to cycle the tank. The decomposing food will be your source of ammonia. Like with the raw shrimp method, there is a risk of Saprolegnia, or mold, occurring in the tank. You can click here to learn more about these risks and what you can do to prevent it. There is no exact science to how much food you will need, but I have found the easiest place to start is dividing your aquarium gallon size by 5. For example if you have a 20 gallon tank start off with 4 flakes, 10 gallon with 2 flakes, 50 gallon with 10 flakes, and so on.  There are different factors that will make every tank cycle differently (like using a pellet or the quality of food,) but your goal is to get your ammonia above 3ppm. Drop in your proper amount of food daily for a few days. After the third day, test your water. If your ammonia isn’t reading 3ppm by this time, increase by a flake (or pellet) or two. Continue to add food every day and only increase the number of food until you have reached above 3ppm. Keep in mind that if you choose to use a large pellet, you may not need to add food daily, just monitor your ammonia levels and make sure to keep a source of decomposing food in the tank. Test your water daily and then add the food, making sure it’s a consistent amount each time. You will first start to notice a spike in ammonia, followed by the presence of nitrites. Then the nitrites will start to spike and the ammonia will start to fall. Continue to consistently add your food daily until you have your nitrates present and ammonia and nitrites at a reading of 0ppm.  Here is a graph showing you what your readings will look like:

Once you have a reading of nitrates and ammonia and nitrites are a 0ppm reading your cycle will be complete and ready for fish. Do a large enough water change so that your nitrates at under 40ppm. You may notice that your tank is a bit messy with this method so I recommend using the gravel vacuum to clean up any particles and waste that may be present.  You may vacuum the top layer of your substrate, but no NOT put your vacuum into the gravel/sand. Only hover above the substrate to skim off the decaying food.

To learn how to do a water change with a gravel vacuum, you can learn more here *coming soon*

For more tips on how to cycle your tank, click here

Add raw shrimp

This method seems to be the most simple and cost effective; but with that being said, keep in mind that it can also take the longest, can smell pretty foul,  isn’t very esthetically pleasing, and creates a risk of Saprolegnia.  To learn more about Saprolegnia and ways to reduce this risk, click HERE.

Here is what you will need:

• 1-2 raw shrimp- which can be found at the grocery store.
• Test kit/strips-though not as necessary
• Media bag

The best way to cycle a tank with raw shrimp is to put one raw shrimp into a media bag and have it sit in your tank. Essentially the whole cycling process with raw shrimp is to simply allow it to decompose in your tank. The media bag isn’t mandatory for cycling, but the decomposing shrimp can become very messy as it breaks down, and the media bag will help by keeping the shrimp pieces together instead of all over your tank. This method can take about a month or two and you will not need to test your water as frequently as with other options. Ideally testing weekly or every 2 weeks which your LFS can do for you. As with other methods your ammonia will spike, followed by nitrite. Nitrates will become present towards the end of the cycle, and once your ammonia and nitrites have a zero reading your tank will be cycled. Once you are ready, remove the shrimp and do a large enough water change to put your nitrates just under 40ppm. Do not gravel vacuum substrate or clean your filter.

For more tips on how to cycle click here.