What is Cycling?
Cycling is a term you might have heard if you’ve ever dug a bit deeper into the aquarium hobby. As I mentioned in the previous section, there’s a whole host of organisms that are a critical part of aquatic ecosystems. These microscopic plants, animals, and bacteria form the foundation of the ecosystem. It’s hard to see the impact they have when you never see them, but they’re important. They adjust the levels of nutrients and chemicals, as well as recycle wastes and other matter into compounds usable by the bigger stuff.
But you have to give them time to do it! That’s what cycling is. It’s what we call the waiting period wherein we impatiently delay the completion of our jarrariums.
How do you begin cycling?
There’s a couple of methods. The first and easiest is to simply use pond water and pond mud in the creation of your jar. These ingredients are already chock-full of micro-organisms and tiny bugs. Simple wait a couple of days for everything to settle in, and you can consider yourself cycled.
Alternatively, you can inoculate your jar with water. If you want to use only gravel as your substrate and omit soils entirely, you can do that. Just add a dash of pond water to the chemically-neutral water you already mixed up. As with the mud, all of the tiny plants and animals in that pond water will begin to multiply and eventually fill the water. Since you’re not using any soil, you won’t need to add any pond mud. Jars without soil will lack some of the ability to decompose, but you can make up for that in other ways (detritivores!). There also won’t be any nitrifying bacteria if you don’t have dirt, so particularly needy plants might suffer. That can be rectified by either using fertilizer tablets or adding “plant food” directly to the water (in a very diluted manner). These can be purchased online or in aquarium stores.
There’s a final method, one that is used very commonly in aquariums. It’s also the easiest (if slowest). You have to obtain an appropriate “live rock” and chuck it in your jar. A live rock is a rock that is “living” in the microbial sense. It has established populations of bacteria and microorganisms because the rock has been exposed to them for several months. People with aquariums will transplant a rock from their old tank to the new one when setting up a tank. Live rocks serve as a catalyst for cycling, just like pond water or pond mud.
What makes a good live rock?
Rocks that are rough, porous, or have lots of nooks and crannies. They shelter colonies of the minuscule creatures that you want in your jar. A smooth rock, like a piece of shale, doesn’t give them much to hold onto. It’s also important that the rocks have existed in a cycled aquarium or jar (or pond) for a few months. That gives them the time they need to soak in all the good stuff. It’s also important that you use a rock from the right setting! You wouldn’t use a rock from a freshwater aquarium to cycle a saltwater aquarium! Those two ecosystems have a totally different assemblage of microorganisms that are adapted to different environments and perform different functions. If you tried putting a live rock from fresh water into salt water or vice versa, everything on the rock would just die in a couple of hours.
How long does cycling take?
After you’ve chosen your method of cycling, you have to wait for the actual cycle part to happen. Ideally, you should wait two weeks after inoculating your jar. I know; it’s a really long time. Between you and me, it’ll still be okay if you only wait one week. The reason we wait so long is because the levels of nutrients and chemicals in the jar fluctuate wildly in the beginning while everything is getting set up. It can sometimes be harmful to plants, but it is particularly dangerous to animals.
Once it is done cycling, you can put in your plants! They will also make a few changes to your burgeoning ecosystem, so you should wait another week after adding plants before you try to put in any animals.
You can monitor cycling by using water test strips. They can be bought anywhere that sells fish. The most important chemicals to monitor are ammonium/ammonia. It can do the most harm to the occupants of your jar. Also, make sure there’s no chlorine or fluorine, but that should only be a problem if you used tap water. Ensure the pH is between 6-8. If you don’t want to use test strips, you’ll be okay. Just wait the entire cycling period. Most chemical problems won’t show up for a couple of months, so you don’t need to start testing until it’s been a while or problems start to crop up.
We’re getting to the fun parts, now! How to choose your plants.
Hi! I’m currently planning out my first jarrarium, and ran into a bit of a problem. I live in a desert and don’t have easy access to a pond to cycle the water. Since I don’t have a previous aquarium to get a live rock from, is there another way to cycle the water? Thanks!
Good question. You don’t actually need live rock to cycle an aquarium. There’s a hypothesis called “Everything is everywhere”, which is basically that every possible microorganism is kinda just… around. Like, in the air and soil. If you just leave a jar of water out long enough, algae will eventually begin to grow, right? Invisible bacteria will colonize it too, it’ll just take a few weeks.
However, you’re probably going to buy some aquatic plants, right? You can put in plants before cycling, and they will carry the bacteria you need 🙂
I was hoping to create a pond in a jar setup, although the purpose will be to maintain the more ‘scummy’ aspects, as I use a microscope to observe and photograph the various critters. I mainly want to sustain the water using an air pump to stop it going off and creating an odour.
I’m unsure if the ecosystem will be any different based on my specific plans, but I was hoping to get some advice on maintaining the water while still having the scummy stuff present? Is it likely to still smell? Is a lid necessary or can I have it open? Will an air stone / pump be enough?
Thanks in advance for any info.
That’s an interesting question. Guess it depends what you mean by “scum”. Algae? The oily layer on the water’s surface (called biofilm)?
The purpose of an air pump in an aquarium is to agitate the surface of the water, increasing the rate at which oxygen diffuses into the water. It usually prevents biofilm from forming. It should also reduce any smells by keeping the water from being “stagnant”.
That said, the biodiversity of your jar is unlikely to change from the presence of a pump. It might change the relative proportions of populations, some microorganisms prefer still water, etc., but there will be plenty for you to look at!
Yes that’s exactly it, the algae stuff and general “good” scum with the diatoms, worms, even bacteria and amoebas, copepods, insect larvae etc
I don’t know if biofilm is interesting to look at,or whether it is important, but the main reason for the air is – as you mentioned – avoiding stagnant water and high levels of bacteria, as well as prolonged well-being of the critters.
(I found my first hydra yesterday but the water is starting to turn.) I’m still working through your site, great info – never tried anything like this before, and hoping to figure out the basics.
Awesome, glad you’re finding success. Good luck with your jar!