Stock a virtual reef tank and watch the care-sheet rules play out — bioload, temperament clashes, and predator pairings, narrated live.
Add livestock and see the tank log flag minimum-size, temperament and predator-pairing conflicts as each resident goes in.
Most stocking advice arrives after the damsel has already claimed the tank. This simulator applies the standard care-sheet rules — minimum tank sizes, temperament, predator pairings, and total bioload — while you build, and narrates every conflict in the tank log as it appears.
Pick a tank, add livestock, and try the three challenges. The full species table with the underlying numbers is at the end.
Stocking mistakes are the most expensive lessons in this hobby, so make them here first. Pick a tank, add livestock, and the simulator applies the standard care-sheet rules — minimum tank sizes, temperament clashes, predator pairings, and total bioload — narrating every conflict as it appears.
| Species | Min Tank (gal) | Adult Size | Temperament | Reef |
|---|---|---|---|---|
| Ocellaris Clownfish | ~20 | ~3″ | peaceful | safe |
| Royal Gramma | ~30 | ~3″ | peaceful | safe |
| Watchman Goby | ~20 | ~3″ | peaceful | safe |
| Cleaner Shrimp | ~20 | ~2″ | peaceful | safe |
| Mandarin Dragonet | ~30 | ~3″ | peaceful | safe |
| Blue Damselfish | ~20 | ~3″ | aggressive | safe |
| Six-Line Wrasse | ~30 | ~3″ | semi-aggressive | safe |
| Dwarf Angelfish | ~55 | ~4″ | semi-aggressive | caution |
| Yellow Tang | ~90 | ~8″ | semi-aggressive | safe |
| Blue (Hippo) Tang | ~180 | ~12″ | semi-aggressive | safe |
| Lionfish | ~120 | ~15″ | aggressive | caution |
Minimum sizes and temperaments are the commonly published care-sheet ranges (~ marks them as such); individual fish vary. Deep dives: the reef tank setup guide · what a 20-gallon can hold · cycling a new tank.