Aquatic Ecosystem

How to complete Aquatic Ecosystem

This is about creating a small contained world that stays alive without constant rescue: stable water chemistry, a working nitrogen cycle, and inhabitants that thrive rather than just survive. The real challenge isn't day one, it's the tank still looking healthy three months later.

1. Pick a tank 20 gallons or larger for fish, or a sealed glass jar/vivarium for a terrarium; bigger water volume forgives beginner mistakes.
2. For an aquarium, cycle it for 2-6 weeks before adding fish: run the filter, dose ammonia or add a hardy starter, and test until ammonia and nitrite read zero.
3. Add a substrate, hardscape, and live plants or moss suited to your light and humidity, then stock slowly so the bio-filter keeps up.
4. Set a fixed routine: weekly 20-30% water changes for fish tanks, or misting and occasional venting for a terrarium.
5. Test water parameters (ammonia, nitrite, nitrate, pH) regularly the first two months and adjust feeding down if nitrates climb.

Tips

• Overfeeding is the number one killer; feed only what's eaten in two minutes.
• Buy a liquid test kit, not paper strips, for the cycling phase.
• A closed terrarium that fogs and self-waters is the lowest-maintenance version of this achievement.

What counts as done

Your tank or terrarium has run for at least a month with healthy inhabitants and stable readings, no crashes or mass die-offs.