Dispenser water creeper farm

Creeper only farm over deep ocean, with glass pillars that stop spiders spawning so nothing but creepers comes out of it. Creepers spawn on stacked slab platforms, dispensers flush each level with water on a redstone clock, and the current carries them down onto soul campfires that kill them without burning the drops. Eighteen chests take the gunpowder. There is nothing to tame, bring or keep alive. Java is what it was built for, though Bedrock builders have a fix for the water. It is five and a half years old and still one of the most built creeper farms there is, but 1.18 changed mob spawning to light level 0 and that is the one thing the original build does not account for.

From 1.18 mobs only spawn at light level 0, and the platform edge sits at light 4. Extend the roof by 3 or 4 slabs in every direction. Two of the highest voted comments say this, one with 368 likes says it is unnecessary, so check the light level yourself before committing.
At 7:01 the video puts a repeater on top of a dispenser. It should be an observer. That is the usual reason the water never dispenses.
Fill the dispensers with water before you build the levels above them, or you will be fighting twenty creepers on each one.
Lower the AFK platform. Builders settle around 71 to 73 blocks above the redstone platform rather than the height in the video.
On a server it only runs properly when you are the only player in the overworld. Spawns collapse as soon as anyone else is there.
On Bedrock the water system does work if you flip the observer so the red eye faces upward.