Target block moss bone meal farm

ilmango's bone meal farm, built here as a tutorial by Adnan Aslam. A lava and water generator makes fresh stone across two mirrored halves, four dispensers bone meal four moss blocks, and the moss spreads over that stone before 93 sticky pistons sweep the growth off. Target blocks and redstone torches drive the timing, packed ice speeds the items along the collection floor, and 31 composters turn the moss products back into bone meal. Part of that output goes back to the dispensers through four droppers so the farm feeds itself, and the surplus lands in barrels and a chest. It does not need to be chunk aligned, but it does need to stay loaded while it runs.

If you build from the schematic it will not start until you put one dirt block in the hopper next to the redstone lamp and torch. MuhammadAffan-r4t and Mr_VictorNX both hit this.
If one side stops making moss, break the four repeaters on that side under the target block next to the packed ice while the farm is running, fill every dispenser with bone meal, then put the repeaters back at 1 tick.
Fill all four droppers with bone meal by hand. lunettagui says that is what took his build up to thousands an hour on 1.21.11.
The schematic is missing redstone on one side, on the third layer connected to the torches above the target block, and the world download is missing two lava sources.
There are sticky pistons and observers down in the ground that are easy to miss when you copy the schematic, so check the lower layers before you switch it on.
It does not have to be chunk aligned, but leaving the loaded chunks with the farm on is what turns the stone into cobblestone. laetitia8218 uses a chunk loader instead.