Unranked
DefaultBest For: Starter tier
Why Keep It: No requirement
When Not to Keep It: 0 compost value
Reroll Priority: Starting tier before you begin submitting seeds.
Build A Ring Farm Wiki
Build A Ring Farm Composter Guide
Learn where to find the Build A Ring Farm Composter, how compost tiers work, which seeds to submit, and how to roll Compost Hydra. Check rewards right now.
Updated: June 3, 2026
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The Composter, also called the Compost Machine, is a Build A Ring Farm feature that lets you submit seeds to fill compost tiers and roll rewards. It can give items such as Super Fertilizer, Void Spray, Radioactive Spray, and the exclusive Compost Hydra seed.
Quick Read
- Location
- Second and third floors of your farm
- Unlock
- Expand your farm until the floors with the Compost Machine are available
- How It Works
- Add seeds, fill compost value, pull the lever, then choose one reward
- Main Rare Reward
- Compost Hydra
- Best Use
- Sacrifice spare high-value seeds instead of low-value crops
Compost Tiers
Requirements may change after updates. We will update this table when new tier data is confirmed.
Rich Compost
5B seed valueBest For: Early reward tier
Why Keep It: First milestone worth targeting
When Not to Keep It: 5B
Reroll Priority: Can roll Super Fertilizer, Void Spray, Super Pet Treat, Strong Fertilizer.
Prime Compost
50B seed valueBest For: Mid-game reward tier
Why Keep It: Can roll Compost Hydra
When Not to Keep It: 50B
Reroll Priority: Target tier for Compost Hydra. Also rewards Radioactive Spray, Super Fertilizer, Void Spray.
Overgrown Compost
25T seed valueBest For: Highest known tier
Why Keep It: Best known reward pool
When Not to Keep It: 25T
Reroll Priority: Can roll Radioactive Spray, Cosmic Spray, Rainbow Spray, Super Pet Treat, Super Fertilizer.
What Is the Composter
Put seeds in, get rewards out
The Composter is a machine in Build A Ring Farm where players can submit seeds to build compost value. Once a compost tier is reached, players can pull the lever and choose one reward from a random selection.
Where to Find the Compost Machine
Second and third floors of your farm
The Compost Machine can be found on the second and third floors of your farm. If you cannot see it yet, keep spending Cash on farm expansions until those floors become available.
How to Unlock the Composter
Expand your farm until the Compost Machine appears
You unlock the Composter by expanding your farm with Cash. The machine becomes available when the floors containing it are accessible. There is no separate quest or item required beyond normal farm progression.
Rewards by Compost Tier
Rich Compost rewards
Super Fertilizer, Void Spray, Super Pet Treat, 2x Strong Fertilizer.
Prime Compost rewards
Radioactive Spray, 2x Super Fertilizer, Void Spray, Compost Hydra.
Overgrown Compost rewards
Radioactive Spray, Cosmic Spray, Rainbow Spray, Super Pet Treat, Super Fertilizer.
Prime Compost Reward Chances
Drop rates based on current public data
The following chances are based on community tracking, not official developer data. Treat these as estimates until confirmed in-game.
See Seeds pageHow to Get Compost Hydra in Build A Ring Farm
Reach Prime Compost tier and hope for the 1% roll
Compost Hydra is an exclusive reward from the Composter. To get it, reach the Prime Compost tier, pull the lever, and hope it appears as one of the selectable rewards. Current public data suggests Compost Hydra has a 1% chance in the Prime Compost reward pool. There is no guaranteed way to get it other than repeated attempts.
FAQ
What is the Composter in Build A Ring Farm?
The Composter is a machine that lets you submit seeds to build compost value and roll rewards.
Where is the Compost Machine in Build A Ring Farm?
The Compost Machine is found on the second and third floors of your farm.
How do you unlock the Composter?
You unlock it by expanding your farm with Cash until the floors containing the Compost Machine become available.
How do you get Compost Hydra?
Reach the Prime Compost tier, pull the lever, and choose Compost Hydra if it appears as one of the rewards.
What is the chance of getting Compost Hydra?
Current public data suggests Compost Hydra has a 1% chance in the Prime Compost reward pool.
Should I use the Composter early game?
Usually no. Early game players should focus on income first. Use the Composter when you have spare seeds or can afford to sacrifice high-value seeds.
Next Steps