Compact moss bone meal farm

A compact self sustaining bone meal farm, designed by Dusty Dude and built here by Shulkercraft. One moss block sits above a small lava and water stone generator. A dispenser bone meals that moss, it spreads over the fresh stone, six pistons break the growth off, and water carries the drops into six composters sitting on hoppers. A dropper elevator lifts the bone meal those composters make back up to the dispenser so the loop closes, and the overflow goes to two chests. Five furnaces sit behind the pistons because pistons cannot move a block entity, which keeps the generator wall in place. The build is small enough for an early survival world and takes about 12 minutes to follow.

Replace the redstone dust at 3:32, the one next to the first sticky piston, with a repeater. This is the fix nearly everybody needs and grantgibson1858 confirms it still works on 1.21.11.
Download the world before you start. hudsonstone2323 found the third hopper at 9:06 points a different way in the working model than in the video, and that redstone at 3:31 is a repeater there.
Leave the fourth repeater on the first redstone clock at 3 ticks. At 4 ticks the generator only makes cobblestone, which is what trunkarrett6295 traced his failure to.
If the bone meal runs out, add a second stone generator on the opposite side and put furnaces behind the pistons either side of it. 47CryXMA went from running short to 660 an hour that way.
If the droppers at 8:34 do not shoot the bone meal up, dig a one block hole beside the redstone on the glass at 10:49 and put a redstone in it.
To run it as a moss farm instead, swap the composters that feed the chest for hoppers and leave the ones feeding the dropper alone.