Ancient Wellspring

?What is a phase?

A habitat block cycles through its pool's phases, one per in-game day (a 20-minute Minecraft day-night cycle). Phase 1 is active on the first day, phase 2 on the second, and so on — after the last phase it starts over at phase 1. A Pokémon listed under phase 2-4 only appears on days 2, 3 and 4 of the cycle. Wild habitat blocks in freshly generated structures always advance in order (1, 2, 3, …).