Quick Answer
Yes, you can keep shrimp and snails in a filtration-free jarrarium using a balanced ecosystem of aquatic plants, beneficial bacteria, and a very low bioload to process waste naturally. A 1-gallon glass container planted with Java moss, duckweed, or Marimo balls can support 2–3 cherry shrimp or a single ramshorn snail without any pump or filter. The key parameter to maintain is a nitrogen cycle equilibrium where plant uptake exactly matches the bioload — achievable at stocking densities below 1 shrimp per 0.25 gallons.
A jarrarium is a testament to the principle that an aquarium doesn't need heaters, filters, or air pumps to thrive—just natural balance. Also known as a no‑tech bowl aquarium, it's a sealed or open glass jar that houses a miniature ecosystem of live plants, substrate, and a very small bioload of animals, most commonly shrimp or snails. It's aquascaping for the windowsill.
How Does a No‑Tech Jarrarium Work?
A jarrarium relies entirely on the natural nitrogen cycle. Aquarium plants, especially fast‑growing species, absorb ammonia directly from the water as a fertilizer. They produce oxygen via photosynthesis, which the tiny inhabitants breathe. The waste from a few small shrimp or snails is negligible and is quickly absorbed by the plants. As long as the system receives indirect sunlight (not direct sun, which will overheat it), it can remain balanced for months.
Step‑by‑Step Jarrarium Build
- Step 1: Choose Your Container (2-5 Gallon): Use a glass mason jar (1-2 gallon), a cookie jar, a glass vase, or a specialty apothecary jar. The wider the opening, the better for maintenance. Ensure it is clean and free of soap residue.
- Step 2: Add Substrate (1-2 inches): Use an inert fine sand or small gravel. A very thin layer of organic potting soil capped with sand (the Walstad method) can work, but it is riskier. For beginners, use plain sand and add a couple of root tabs later.
- Step 3: Add Hardscape: One small, smooth rock and a tiny piece of driftwood can add structure and provide surface area for beneficial bacteria. Boil the wood first to sterilize it.
- Step 4: Plant Heavily: This is the most important step. Plant at least 70-80% of the substrate. Use easy, low‑light plants. Excellent choices include Java Moss, Marimo Moss Balls, Dwarf Hairgrass (may need more light), Anubias nana petite (tie to hardscape), and small Cryptocoryne species. Floating plants like duckweed or Salvinia are also very helpful.
- Step 5: Fill and Cycle: Slowly add dechlorinated water to avoid disturbing the substrate. Leave 1-2 inches of air at the top. Place the jar in a spot that receives bright, indirect sunlight. Let it sit for a full 4 weeks to cycle before adding any animals. You should see active plant growth and no foul smells.
Best Animals for a No‑Tech Jarrarium
- Neocaridina Shrimp (Cherry Shrimp): The best choice. They are small (1 inch), incredibly hardy, and will graze on biofilm and algae. A small jar (1-2 gallons) can support 5-10 cherry shrimp.
- Ramshorn Snails: Very effective cleaners. They are prolific, so population control may be needed.
- Malaysian Trumpet Snails (MTS): Burrow in the sand, which aerates the substrate. They are nocturnal and can become very numerous.
- Bladder Snails: Small, pest snails that appear on plants. They are excellent cleaners, but some consider them unsightly.
- Avoid All Fish: No fish can humanely live in a 2‑gallon jar. Even a single betta needs a minimum of 5 gallons with a filter and heater. Do not keep any fish in a jarrarium.
Maintenance: Almost None
This is the allure of a jarrarium. It requires no filter, no heater, and no air pump. Maintenance includes topping off evaporated water with dechlorinated freshwater once a week, performing a 25% water change every 2-4 weeks to remove the slow buildup of nitrates, and trimming overgrown plants. If you see a spike in algae, reduce the amount of light.
Jarrariums are a fascinating, low‑entry project that demonstrates the power of nature. They are perfect for a desk, a bookshelf, or as a beautiful, living art piece that requires almost no technology or effort to maintain. They are not a permanent home for most animals, but for a small colony of cherry shrimp, they can be a thriving, miniature world.
Knowledge Journey
Recommended Next Steps
Move from reading to action with related calculators, fish profiles, and quiz-based recommendations.
Calculator
Aquarium Layout & Inspiration Builder
Choose an aquascaping direction based on hardscape, plants, maintenance level, livestock, budget, and whether you want a low-tech or high-tech layout. Avoid random decor and build a tank that suits your fish and your routine.
Calculator
Annual Fish Keeping Cost Calculator
Estimate the true annual cost of your aquarium by entering tank volume, heater wattage, filter and light power, heater runtime, and local electricity rate. Get a practical itemized breakdown for heating, filtration, lighting, water, and routine consumables before you set up, upgrade, or troubleshoot a tank.
Calculator
Aquarium Filter Turnover Rate Calculator
Never buy an underpowered filter again. Calculate exactly how much flow your aquarium needs to keep water clear, ammonia zero, and fish healthy — based on your specific tank size, stocking density, and fish species.
Quiz
Fish Compatibility Quiz
Find beginner-friendly fish that match your tank size, setup, and experience level.
Quiz
Fish Quiz Hub
Choose a guided quiz and get personalized fish care next steps.
Calculator
Ammonia Toxicity Calculator (Free NH3)
Enter your test kit reading (TAN), pH, and temperature — get an instant SAFE or LETHAL verdict for Free Ammonia (NH3). Built for API Master Kit users, cichlid tanks, reef setups, and fish breeders.