Minecraft wiki entry for Squid_farming, associated text: Squid will spawn in 1 or more blocks of water, no matter whether it's a water source or flowing water. Squid can also spawn in bubble columns, (Bedrock Only) so an upwards column may be used for collection. Note that downwards columns do not pull the squids, making them considerably less useful for squid farming. The level of light is not important. However, they will only spawn if their spawning block (the solid block underneath the water) is between Y (vertical) level 50 and 62, inclusive.