Maintenance in Jarrariums

One of the primary goals of a jarrarium is little-to-no maintenance. The term “self-sustaining ecosystem” by its very nature means that, once set up, you shouldn’t have to ever touch it again.

Despite our best efforts, this probably won’t be the case. Aquariums, in general, require a lot of maintenance. Like we’ve discussed before, the small size of the jarrarium will concentrate some of the toxic chemicals and require more frequent attention. This should be offset somewhat by the low-bioload we have since we didn’t include any vertebrates.

If you are attempting a sealed, entirely self-sustaining jar, you don’t even need to read this section. The scenario you created when you sealed the jarrarium will have to be sufficient to maintain life by itself.

Water Change

The first and most obvious maintenance an aquatic ecosystem will require is regular water changes. In a natural system, flowing water or cycles of evaporation and rain will change the water. Build ups of various chemicals and debris are removed by organisms, and sometimes by geological processes. We have some of these processes present in jars, but to a much lesser degree.

maintenance jarrarium


To supplement them we change the water manually. The frequency with which you change the water fluctuates based on the composition of the occupants of your jar. Do you have a lot of animals? If so, you need to change it frequently – at least once a week. If you have a lot of plants, though, you won’t need to change it as frequently. They act as a sort of filter, helping rid the jar of excess nutrients and sometimes even toxins. Do you have a soil or mud substrate, and was your jar cycled with mud from a pond? If so, you have an invisible, yet thriving, population of bacteria that help deal with excess nutrients. You won’t need to change the water as frequently.

There are many factors that impact how frequently you need to change your water. If you’re unsure, do it once every two weeks. If you have a low bioload or a high one, adjust accordingly. When you change the water, be sure that you replace at least half of it. Remove water by scooping it, or by using a water siphon (available at all pet stores). When adding more water, make sure you use treated water (like we detailed in the water section). Pour slowly, or pour over the back of a spoon, to prevent kicking up clouds and disturbing the occupants.

You don’t have to do water changes. If you’d prefer to perform no maintenance, it’s entirely possible your jar will survive for months or years. The environment inside will become progressively more stressful to the inhabitants, however. The best way to maintain a jar in its current condition is to do regular water changes.


If you have healthy plants, you’ll eventually find that they risk overcrowding your jarrarium. In a jar, these aquatic plants have the perfect conditions: plenty of light, no predators, few competitors, ample nutrients. They love it.

Trimming aquatic plants is just like trimming terrestrial ones. It can be made difficult, however, by the vessel you chose to make a jarrarium in. If the neck is too narrow for your hand to fit through, you might be out of luck. They do, however, make tools to address the issue. There are long-handled scissors that can reach in and snip plants. There also exists miniature claws to grab the clippings afterwards. Whatever the tool you use, make certain it is sharp. Having clean cuts helps a plant recover from the injury, and reduces the likelihood of infection.

Although it isn’t heavily important, trimming plants in certain fashions can be important. If your plant grows leaves at nodes, where all the leaves come from the same section of the stem, you generally want to trim right above a node. If you’re ascribing to a certain style of aquascape, take into consideration the guidelines for that style!


As in all facets of life, cleaning is the worst. Most jarrariums will need to be cleaned every month or two. Dead plant and animal debris will begin to accumulate on the bottom. Algae will start to creep up the glass sides of your jar. When your jar is ugly, it’s time to clean (unless you’re mimicking a pond – those are always ugly, no cleaning necessary). It’s important to clean your jar occasionally. If you leave too much dead stuff in the jar it can impact the chemical levels in the water.

Getting all the crud off the bottom can be accomplished in a couple of ways. While a bit extreme, you could replace all the substrate. Obviously, this is easier if you just have gravel or sand. However, you run the risk of disturbing your plants or animals. While cloudy water doesn’t bother aquatic organisms, dramatic changes can stress them out. A better option is to “vacuum” the bottom. With either a siphon or an aquarium vacuum you can suck up water and debris from the bottom of a jar. You generally want to do this when it is time for a water change anyway, as you’ll lose water in the process.

You’ll also want to get rid of that algae growing on the glass, too. You can always use an algicide, of course (don’t use a copper-based one if you have shrimp). They tend to be less effective on glass-growing algae than the other kind, though. A sponge or steel wool is a very efficient way to remove it if you can fit your hand in the jarrarium. Try to scrub the glass near the surface of the substrate. It’s unlikely you’ll be able to remove all the algae, but it should look better (temporarily).

Finally – How to Assemble your Jarrarium!