Kelp Farm

Beginner Java + Bedrock

Produces: Kelp for smelting into dried kelp - food, and dried kelp blocks that smelt 20 items each

How it works

• Kelp only grows underwater, planted on a block with a full top face (not magma) in a water source or downward-flowing water - and it lives in every ocean biome except warm, frozen and deep frozen oceans.
• Each kelp plant has a hidden age (0-24, check with F3 in Java): every new block of growth adds 1, and at age 25 it stops - so natural stalks top out between 2 and 26 blocks tall.
• The farmer's trick: breaking any kelp block re-randomizes the age of the block below it, so stalks keep regrowing - and breaking the second block from the bottom drops the entire upper stalk as items at once.
• Bone meal works on kelp - a dispenser with bone meal under each plant turns a slow natural farm into a fast one.
• Fuel math: 9 dried kelp craft into a dried kelp block, which smelts 20 items (2.5x coal per item slot). Net gain is 11 smelts per block after the kelp you burned to dry it - use lava buckets or campfires for the first drying and the loop is pure profit.
• Smelting kelp also gives XP - a kelp farm feeding furnaces doubles as a quiet, safe XP bank when you empty the furnaces by hand.

Materials

• A few kelp from any cold or lukewarm ocean
• Building blocks for the water column (glass to watch it grow)
• Water buckets
• Dispensers + bone meal + observers for the automatic version
• Furnaces or smokers, and hoppers with chests

Build steps

1. Gather starter kelp: dive any ocean that is not warm or frozen - kelp breaks instantly by hand and the whole stalk above the break drops.
2. Build the column: a vertical water tube over a solid base block, one kelp planted at the bottom per column.
3. Harvest smart: break the second block from the bottom - the plant stays rooted and everything above pops off as items.
4. Automate it: an observer watching the top growth fires a piston that breaks the stalk, and water currents carry items to a hopper.
5. Add bone meal: a dispenser under the plant, triggered on a clock, forces constant growth - kelp accepts bone meal, unlike sugar cane or cactus.
6. Dry the kelp: furnaces or smokers turn kelp into dried kelp - eat it in a pinch, but craft 9 into blocks for fuel.
7. Close the loop: dried kelp blocks smelt 20 items each, so the farm fuels its own drying with plenty left over for your other smelting.
8. Harvest furnace XP by hand: pull the dried kelp out manually and the stored smelting XP flows to you.

Rates

A single manual column yields a few kelp per minute; an observer-piston module with bone meal produces stacks per hour and fuels itself. One dried kelp block smelts 20 items - net +11 after drying costs.

Tips

• Plant on any full-top-face block except magma - magma turns the water column into a bubble elevator that sucks the kelp down.
• Campfires dry kelp for free - slow, but the first batches cost zero fuel while the loop spins up.
• Keep the farm in a spawn chunk or near your base: kelp only grows in loaded chunks like every crop.
• A kelp column in a water stream converts flowing water into sources - the classic cheap bubble-elevator trick, free with the farm.

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