Woo, what a long time in the making. First of all, a huge WOOP to Sakura for.. well everything she does, and for not rushing me on this, because I took my sweet time. I'd also like to thank my dear friend Hallyx, for all his input and cycling knowledge. We'd be no where on BettaFish without these two sweeties around. Additional thanks goes to Chesherca, for going through my work as well, making sure everything actually made sense to someone other than myself.
Things you will need:
- A filter (Hang-on-back (HOB) and sponge are most popular with betta)
- An ammonia source (this could be pure ammonia, fish food, raw shrimp, or even your fish, depending on the method you choose)
- Plants (if you plan on doing the planted method)
- A small oral syringe (meaning without a needle!) is useful when using pure ammonia, usually a 5mL size is best. These can be found in pet stores in the dog/cat section, or in pharmacies in the baby section, as they are used to measure out dog/cat/baby medicines. Only needed for pure ammonia method.
-Tank (and possibly bucket for a bucket cycle), substrate, decorations, all of which provide surface area for your bacteria to grow.
-A test kit for ammonia, nitrite, and nitrate. An API Master Test Kit gives the best value over the long run, but strips can also work fine.
About the Nitrogen Cycle: There is tons of info on this, but I want to sum this up as briefly as possible. The nitrogen cycle is when you "grow" bacteria in your tank, on your filter and everything else in the tank. Fish produce ammonia, which is bad for them, it damages their bodies, causing burns and death. The bacteria consume the ammonia, and produce nitrite. Now, nitrite isn't any better and can do just as much damage as ammonia, so another type of bacteria consumes it to make nitrates. Nitrates are the last step of the cycle, and are much less toxic, but still hurt in the long run, which is why it's important to do weekly water changes of 30-50% in a cycled aquarium.
First Thing's First- The Method: There are five distinct methods for properly cycling your tank that we'll be looking at in this article. Any of these methods will achieve the end-result of a fully-cycled tank, but only you can decide which will work best for your situation. You can safely cycle a tank of any size using the techniques listed here. Some people prefer not to cycle smaller tanks, instead relying on more frequent water changes to keep the water clean. However, if you plan to keep a larger tank of five to ten gallons or more, it will be necessary to cycle the tank for the health and safety of the fish who will be living there.
1. Fishless cycle using pure ammonia:
This has quickly become the most popular method of cycling, accurate and easy to follow, if you can find the right stuff! Basically, you want to dose pure ammonia into a tank with no fish or plants.
Pros: Easy to follow, accurate, no risk of mould infestation. Dosing large amounts of ammonia initially allows for a larger amount of fish to be added initially (in communities). Cons: Pure ammonia cannot be found in all countries, there is a risk of other ingredients. If there are no ingredients listed, shake the bottle around. There should not be any foam that looks like soap bubbles.
Ammonia is toxic to all life, dosing these high levels of ammonia does put aquatic plants under risk. Ammonia is an irritant that can burn the skin and eyes. It is best to wear gloves when dealing with ammonia. Always be careful!
This method is where the pure ammonia and the 5mm syringe come into play. Basically you want to dose at 2-5ppm ammonia initially. Ammonia should never be higher than 7ppm, this can stall your cycle. Test for ammonia and nitrite every 2-3 days. Replenish ammonia to original levels as you see it fall down. This is considered the longest part of the cycle process.
Once you see nitrites, you will probably notice they skyrocket up extremely fast, even “off the charts” for your test kit. This is fine and completely normal. Keep dosing ammonia to the required amount. Once nitrites have peaked, it is generally only a few days before they get back down to zero. When you see nitrites going down, start testing for nitrates, which should start appearing.
For your final test, wait until your ammonia is pretty much at zero, and dose to 2ppm. When ammonia falls to 0ppm within 24 hours (or less) your tank is cycled!
Now, do a large water change, 75-85%, and you are ready to add your fish!
But how do I know how much ammonia to add?
With your trusty 5mm syringe and ammonia bottle in hand, head over here.
The calculator is at the bottom- “Fishless Cycling- Ammonia Required.” Fill in the information, and it will tell you how many mL of ammonia you need. Be sure not to forget to change the settings to gallons if that’s what you use! The % of Ammonia strength will be written on the bottle.
*If your tank already has 1ppm of ammonia, just calculate enough for 3ppm to get it back to 4ppm.
2. Fishless cycle using fish food or a raw shrimp:
The oldest method of fishless cycling involved dead feeder fish. This is a recipe for disease, so the change was made to using fish food, or a raw shrimp. These provide the ammonia at a steady rate as they decompose.
Pros: Ammonia is released steadily. Good substitute when pure ammonia cannot be found. Cons: Generally only small amounts of ammonia will be released by fish food. Higher ammonia levels can be reached using lots of fish food. Shrimp will give a high ammonia reading. It’s important to watch that ammonia doesn’t get over 5ppm. Shrimp in particular, but also flakes, are prone to moulding over (see below.)
Process: After you have your tank set up, just plop in your shrimp. If you’re using fish food, crush it to powder before you sprinkle it in. It’s hard to say how much food to use, so you will have to test your water daily. If using shrimp, it’s nice to put it into a piece of clean pantyhose and tie it up. The shrimp will be very rotten by the end of the process and the pantyhose helps keep it together and makes it easier to clean up.
If you notice the ammonia gets over 5ppm remove the shrimp and do a small water change. It helps to have a strong nose for this method. If using fish food, use cheap food. Ammonia is ammonia, there’s no point in dumping in $20 of a high quality brand.
It’s important to keep ammonia levels in the desired range of 2ppm-5ppm throughout the whole cycle.
Eventually— several weeks, generally — the ammonia will go down. Once you see nitrites, you will probably notice they skyrocket up extremely fast, even “off the charts” for your test kit. This is completely normal. After that, in a few days, the nitrites will go down and nitrates will appear.
Once you have a reading of 0.0ppm ammonia and 0.0ppm nitrites, remove the food or shrimp. Congratulations! Your cycle is done. Do a large water change of 75-85% and add your fish. I wouldn’t wait more than 2 days after removing the food or shrimp to add the fish, the bacteria will be fine for a few days but after that it can start to die off.
A fuzzy white mould has appeared on the food or shrimp!
This is a pretty common problem, especially when using shrimp. There’s hundreds of species of mould and there’s no point in identifying what sort it is. Often, the mould is harmless. Other times it isn’t. Most often the concern is that it’s the mould that causes columnaris in fish. Truth be told, this fungus most likely already exists in your tank, in small amounts. When you see the mould is a sign that it’s reproducing and its population growing (because you fed it).
An easy fix is to dose Pimafix as required. It won’t harm the cycle so it’s safe to use. Replace any food with fresh food (to maintain the cycle) and once the (mould) is cleared up, do your water change and continue. (Pimafix concerns some as being toxic to betta and other labyrinth fish, however the water change you perform will clear most of it out of the water (only in large doses does it affect fish).
3. Fish-in cycle:
What many put their fish through in the beginning without knowing about the cycle. Though it can be hard on fish, if you are diligent in water testing and performing water changes, you can get through it with your fish.
Pros: Well, not a preferable method of cycling. However it is fine if you have brought home fish without knowing about the cycle, just will take a little extra work on your part now. Done properly, lightly stocking a large tank, it will have minimal effects on hardy species (betta are generally considered hardy, however avoid this method if your fish seems sickly in any way). Cons: High levels of toxins put fish under stress, and often cause death without proper action. You will have to perform many water changes and test water very frequently.
Process: So, fish have been added. They will produce the ammonia to get the cycle going. If you choose to do a fish in cycle, it is best to start with a small amount of fish in the tank to keep things under control. Doing 25% water changes whenever ammonia hits .25ppm is recommended. There will still be minute amounts of ammonia starting your bacterial colony, even after water changes. Eventually, nitrites will start showing up. Again, 25% water change whenever nitrites hit .25ppm. Once you start seeing nitrates, you know you have made it through the cycle with your fish! With the fish in cycle, you want to add fish slowly over the course of several weeks to your tank. Once your tank is fully stocked and everything is in order, you can start a regular water change schedule of 30-50% a week.
4. Planted tank:
Planted tanks are a great way to keep the water healthy for fish. Note, I will not be covering the Walstad Method of the planted aquarium- which on here is abbreviated to NPT and requires the use of soil. Walstad method is different from a regular planted tank, so I suggest you research it before putting soil in the tank.
Pros: Plants are natural filters for ammonia and nitrates (some plants also cover nitrite). Planted tanks are a great choice if your tap water has readable ammonia levels or high nitrates. A well planted tank can be stocked much earlier than a tank that must undergo a cycle. Cons: Well, let’s face it: some of us are not green thumbs. Though I personally have much more success with underwater plants than land plants, so it’s worth a shot! Plants must be kept healthy in order to do their jobs properly, which requires proper lighting first and foremost.
Process: There isn’t much to the process, but I will give a few pointers.
During the process, bacteria do grow, but much less than normal because the plants take care of a lot of toxins. Bacteria and plants will balance themselves out, and when done properly, you will never notice any toxin spikes. Some plants are better at absorbing ammonia than others- some easy ones include hornwort, anacharis, duckweed and frogbit. Slow growing plants like Amazon sword and java fern aren’t the best for the job as they absorb much less ammonia.
As a starter, you want to look for fluorescent lights with a kelvin rating of 6500-7000. Most fluorescent lights will say their kelvin rating, and if they don’t, you should avoid them. Lights can be purchased at pet shops, or even at hardware stores. For deeper tanks, you may want to add more lights to allow more light to reach the bottom.
There are many special substrates for planted aquariums; however these are pricey, and eventually wear out. I prefer to use regular sand myself, though small gravel works just as well for plants. Carbon dioxide injection works well, but is pricey and completely unnecessary for most plants. There are liquid forms of carbon dioxide, but these again I suggest avoiding, as they make certain plants (Vallisneria comes to mind) simply die.
If desired, a liquid fertilizer or “root tab” may be used, but these are also not needed to succeed. These contain minerals, and you have minerals in your tap water, so with water changes you do keep mineral levels up. Not to say they don’t help, some plants such as Amazon swords truly do appreciate root tabs.
That having been said, research every single plant before making a purchase. Our shops are full of plants that are non aquatic, as well as “high maintenance” plants that will require high light, as well as carbon dioxide injection in the long run.
A final note- there is no guidelines for how many plants you need for however many fish. My advice, start as heavy on plants as possible and light on fish. Test water and if it stays perfect, you know your plants are doing their job and can slowly raise your fish amount up.
5. Fishless bucket cycle:
A common method, though not often brought up here. If you feel the need to avoid fish in cycling a tank, you can simply place the filter in with a bucket of water and dose ammonia into the bucket. Afterwards, simply place your cycled filter on the tank.
Pros: You can dose ammonia to higher amounts in a bucket, which is useful if you have a lot of fish in your uncycled tank. Meanwhile you can keep ammonia levels low in your main tank, reducing stress to the fish. Cons: This will still require many water changes on your part in the main tank (especially if it is well stocked).
Process: With your filter in a bucket of water (don’t forget to dechlorinate it!), choose either the ammonia or fish food/shrimp method for the bucket. You can also choose to put any décor items or even some substrate you have in the bucket, for bacteria to grow on those surfaces as well.
Meanwhile, your fish stay in their own tank, follow the water change schedule of the fishless cycling method, keeping toxins low. Small, frequent water changes will keep things safe for the fish. *********************
After the cycle:
Once you see your nitrates growing and growing, with everything else at 0ppm, you are done! At this point, since your tank is still “young,” it is best to start off with smaller weekly water changes for a few weeks before moving on to larger ones. As for keeping your cycle going, do not scrub/rinse any decorations, or your filter, and do not allow these to dry out! This will only kill off your valuable bacteria you’ve worked so hard to grow!
Your next fish tank:
The best thing about cycling is: you only have to do it once! If you ever decide to start a new tank, just throw in some substrate or décor from your cycled tank and you have some bacteria ready to go! You can also use part of your filter media. Up to 1/3 of your filter contents can be removed safely in order to start a new tank. This is a quick and easy way to “skip” the long cycling process. Your current bacteria will quickly take over the next tank. As always, I suggest you monitor all your ammonia, nitrite, and nitrate levels with your test kit, just to be sure things are going the way they should.
Well, this is it! Changes may be made in the future, things added or removed, as I see fit.
Very nice and easy to understand ! I just did a fish in cycle and Perseus was a real trooper to put up with all the water changes, but really he likes water changes and may miss not having to do as many now. The API water testing kit is a must I could not have done it without it and also thanks to Hal for answering so many questions I had. Thanks for the time you put into doing this for us Olympia !!!!
Also using Prime water conditioner helped put my mind as ease since it detoxifies ammonia, nitrite and nitrate but only for 48 hours I think but plenty time in case there were any spikes to do a water change. This forum is awesome !
So awesomely thorough! Aww, Olympia, thanks so much for doing this. *hugs*
A quick note to people: originally, it was planned to have Bahamut's diagram as a part of this guide. However, she has respectfully declined to have it added so that is why it isn't appearing. We're all sad not to have it included but of course, the diagram is still available in its original thread on the forum as well.