I'd like to request that this bug report be reopened and unmarked as duplicate. The linked issue is only related to light levels and is marked "won't fix". This issue is about glow squids spawning in mob farms and item streams below a certain level with no way to stop them and, to me, seems like a fairly significant (and distinct) problem that should be looked into more.
The squids consistently spawn in any water below Y 30. Eventually, they move into a non-water block and die, dropping glow ink sacs. The ink sacs are the problem for farms and item transport streams, because whatever the player has designed must now accommodate the random injection of an unexpected item type into the system if any part of it is water below Y 30. If the system doesn't (or can't) handle the ink sacs, it will break. This is a drawback to anyone hoping to utilize the new world depth introduced in 1.18, especially because it is very common for farms or sorting systems to utilize water in some capacity.
Several of my builds were clogged by glow squid ink soon after I upgraded to 1.18. I can't stop glow squids from spawning because the only way to do so is to move the entire system up above Y 30 or stop using water, neither of which is feasible. I can't easily create an item filter to remove the ink sacs without reworking large parts of the build. This is frustrating for me, and I can only imagine what it would be like for a non-technical player following a tutorial to have their system not work and be unable to figure out why or what to do about it.
Since light levels are apparently not going to be used to control glow squid spawns, there should be another mechanism to do so. The simplest would be to adjust glow squid spawning to be in line with other water creatures and have them only spawn if the block below them is water/waterlogged and the block above them is water. Other options could be checking for non-spawnable blocks 2 blocks below or making them only drop items when killed by a player.
Mooeing-747
I'd like to request that this bug report be reopened and unmarked as duplicate. The linked issue is only related to light levels and is marked "won't fix". This issue is about glow squids spawning in mob farms and item streams below a certain level with no way to stop them and, to me, seems like a fairly significant (and distinct) problem that should be looked into more.
The squids consistently spawn in any water below Y 30. Eventually, they move into a non-water block and die, dropping glow ink sacs. The ink sacs are the problem for farms and item transport streams, because whatever the player has designed must now accommodate the random injection of an unexpected item type into the system if any part of it is water below Y 30. If the system doesn't (or can't) handle the ink sacs, it will break. This is a drawback to anyone hoping to utilize the new world depth introduced in 1.18, especially because it is very common for farms or sorting systems to utilize water in some capacity.
Several of my builds were clogged by glow squid ink soon after I upgraded to 1.18. I can't stop glow squids from spawning because the only way to do so is to move the entire system up above Y 30 or stop using water, neither of which is feasible. I can't easily create an item filter to remove the ink sacs without reworking large parts of the build. This is frustrating for me, and I can only imagine what it would be like for a non-technical player following a tutorial to have their system not work and be unable to figure out why or what to do about it.
Since light levels are apparently not going to be used to control glow squid spawns, there should be another mechanism to do so. The simplest would be to adjust glow squid spawning to be in line with other water creatures and have them only spawn if the block below them is water/waterlogged and the block above them is water. Other options could be checking for non-spawnable blocks 2 blocks below or making them only drop items when killed by a player.