Guide
The terrarium guide
How a sealed jar keeps itself alive, and everything you can put in one, with the numbers the simulator runs on.
Basics
- The jarA sealed jar waters itself: plants breathe water out, it beads on the glass and runs back down.
- LayersBottom to top: drainage, a barrier, soil, then a top dressing.
- PlantsSmall, slow and alike in what they want.
- MossNo roots: moss drinks from the air and the surface it sits on.
- Cleanup crewTiny animals that keep a jar from rotting.
How it works
- Needs and healthEach day every living thing scores its needs; health follows the score.
- Death and hazardsOnly hazards kill, each rising from zero at its threshold.
- SoilLayers drain, hold water, feed plants and set the pH the roots feel.
- WaterSoil fills to what it can hold; the rest drains to the drainage layer.
- Humidity and the lidSealed jars keep every drop; open jars lose water to the room.
- LightThe day's light, brightness times hours, drives growth.
- TemperatureThe jar follows the room, a little warmer under a lamp.
- PlantsPlants grow on light and food, share space, and stop at the lid.
- MossMoss creeps from its edges in damp air and browns back when dry.
- CrittersEach crew is a colony that grows to what the jar can feed.
- MouldWhite mould blooms on fresh organics and leaves; springtails eat it.
- CareMist, water, vent and tidy, by hand or on a routine.
- Chance and forecastsTwo things are random; everything else repeats exactly.
- Checked against real jarsFourteen jars their owners described online, rebuilt and run: all fourteen turn out the way the real ones did.
Starter jars
Encyclopedia
- PlantsEvery plant you can grow, with the light, humidity, temperature and soil it needs, and what kills it. 49 entries.
- MossCarpet, cushion and aquarium mosses: how fast they spread, where they grow, and the air they need. 31 entries.
- CrittersThe cleanup crew: springtails, isopods, worms and snails, what they eat and how big a colony a jar can feed. 10 entries.
- Soils and layersDrainage, filters, soils and top dressings: how much water each holds, its pH, and how fast it rots down. 41 entries.
- Stones and woodStones and wood for the scene, and which mosses can climb them. 32 entries.
- Moulds and filmsThe fuzz, films and diseases a jar can grow, what sets them off and what keeps them down. 10 entries.