Minecraft wiki entry for Skyblock, associated text: By using two sources of water, usually included in a chest or as ice blocks apart of the island, you can create an infinite water source. Dig a 2x2 hole 1 block deep, place two water sources in opposite corners, and the merging flows will create new water source blocks. Use a bucket on any of the now-four water blocks, and the removed water will be replaced by a new water source block when the flows merge. If the source blocks are too far apart, the merging flows will be too weak to create a source block, and so cannot become infinite.