Minecraft wiki entry for Skyblock, associated text: Another option is placing a cauldron below open sky and waiting for rain, which will very slowly fill the cauldron with water. When the cauldron is full, you can empty it with a bucket. With 2 bucketfuls of water, you can make an infinite water source. If you're playing on versions above 1.13, you can also use Bone Meal in water to spawn seagrass and more water sources, which you can then pick up with a bucket.