Kelp and sea grass grows up into flowing water and makes it a source block

introduced primarily in pre-3

introduced primarily in pre-3

Isn't this "works as intended?" 

Isn't this "works as intended?" 

Affects 1.13.1-pre2.

Confirmed in Release 1.13.1

Confirmed in Release 1.13.1

Please leave this alone, it's useful for making water elevators with bubble columns and doesn't affect the game otherwise.

Please leave this alone, it's useful for making water elevators with bubble columns and doesn't affect the game otherwise.

@James Spatig It messes up farms that use bonemeal, and isn't intended behaviour either

@James Spatig It messes up farms that use bonemeal, and isn't intended behaviour either

yah if you are trying to make a kelp farm and you didn't make it deep enough it can seriously mess up the farm by causing items to not move towards the hoppers due to the flowing water blocks becoming source blocks.

yah if you are trying to make a kelp farm and you didn't make it deep enough it can seriously mess up the farm by causing items to not move towards the hoppers due to the flowing water blocks becoming source blocks.

I understand why they did this, otherwise a single missing source block in the ocean could ruin the growth. However this is still an oversight.

In my opinion, it should only be able to grow into flowing water (and turn it into a sourceblock) if the block above is also water (source or flowing). This would make it the best of both worlds, the kelp mechanic to create functional bubble columns can stay and farms will not be ruined.

From a logical perspective, this also makes the most sense in my opinion as it would still allow kelps to grow normally in the ocean while preventing weird behaviour like this:

I understand why they did this, otherwise a single missing source block in the ocean could ruin the growth. However this is still an oversight.

In my opinion, it should only be able to grow into flowing water (and turn it into a sourceblock) if the block above is also water (source or flowing). This would make it the best of both worlds, the kelp mechanic to create functional bubble columns can stay and farms will not be ruined.

From a logical perspective, this also makes the most sense in my opinion as it would still allow kelps to grow normally in the ocean while preventing weird behaviour like this:

Just to clarify: Growing Kelp shouldn't create water source blocks, but players should be able to place Kelp in order to create water source blocks.

Just to clarify: Growing Kelp shouldn't create water source blocks, but players should be able to place Kelp in order to create water source blocks.

Affects 1.16-rc1, a growing kelp created a water source block

Affects 1.16

Affects In 1.16.1 and 20w29a

Can confirm in 20w49a.

Can confirm in 21w03a.

Can confirm in 21w06a.

Can confirm in 21w11a.

Can confirm in 21w14a.

Can confirm in 1.17.

Can confirm in 1.17.1. I always thought this was intended.

Seems to work in another world in what acts like the Nether in the infinite snapshot. Also works in the Nether in 1.17.1 (with cheats to place some water to start flowing).

The kelp creates a water source block wherever placed in water. One water bucket and kelp can create an infinite water source, if done right, no bone meal or growth time needed.

Seems to work in another world in what acts like the Nether in the infinite snapshot. Also works in the Nether in 1.17.1 (with cheats to place some water to start flowing).

The kelp creates a water source block wherever placed in water. One water bucket and kelp can create an infinite water source, if done right, no bone meal or growth time needed.

Can confirm in 21w39a.

Can confirm in 1.18.1.

Can confirm in 1.18.2.

I can confirm this in 22w17a. Here's a code analysis of this issue.

The following is based on a decompiled version of Minecraft 1.18.2 using MCP-Reborn. 

Code Analysis:

net.minecraft.world.level.block.SeagrassBlock.java

public class SeagrassBlock extends BushBlock implements BonemealableBlock, LiquidBlockContainer {
   ...
   public void performBonemeal(ServerLevel $sl, Random $r, BlockPos $ps, BlockState $bs) {
      BlockState blockstate = Blocks.TALL_SEAGRASS.defaultBlockState();
      BlockState blockstate1 = blockstate.setValue(TallSeagrassBlock.HALF, DoubleBlockHalf.UPPER);
      BlockPos blockpos = $bp.above();
      if ($sl.getBlockState(blockpos).is(Blocks.WATER)) {
         $sl.setBlock($bp, blockstate, 2);
         $sl.setBlock(blockpos, blockstate1, 2);
      }

   }
   ...

net.minecraft.world.level.block.KelpBlock.java

public class KelpBlock extends GrowingPlantHeadBlock implements LiquidBlockContainer {
   ...
   protected boolean canGrowInto(BlockState $bs) {
      return $bs.is(Blocks.WATER);
   }
   ...

If we look at the above classes, we can see that seagrass requires Blocks.WATER above it in order to grow and similarly, kelp can only grow into Blocks.WATER. Since Blocks.WATER includes both flowing water and water source blocks, both kelp and seagrass can grow into flowing water.

Can confirm in 1.19.

Can confirm in 1.19.2.

Can confirm in 1.19.4 and 23w17a

Confirmed in 1.21.4 prerelease 1

Confirmed in 1.21.4 prerelease 3

Can confirm in 1.21.4 release candidate 3.

Confirmed in 1.21.4

Affects 25w05a