Fluid Flow Controller
Fluid Flow Controller stops water and lava from flowing and from triggering block updates, and it can be switched on or off by server operators without a restart.
What it does
The Fabric mod cancels fluid flow propagation in FlowableFluid, along with the scheduled fluid ticks and the block updates that water and lava would otherwise cause. Because the flow is stopped at the source, spreading and recalculation no longer run on the server, which the author describes as a way to keep server performance under tighter control.
Operators with permission level 3 or higher run the ffc command to toggle the behavior in real time. Access can also be granted through the ffc.toggle permission node once a permissions plugin is in place. The mod is implemented with Mixins and bundles fabric-permissions-api for that node check, so no restart is needed to change it.
The mod is published for 1.21.1 on Fabric only, at version 1.0.1 dated 2025-10-12. Installation needs Fabric Loader and runs on dedicated servers, including Arclight-based Fabric servers. It is released under the MIT License and is open source, with public source code and an issue tracker.
Key features
Fluid flow disabled
Water and lava stop spreading across the world, so flowing fluids no longer advance block by block.
Scheduled ticks cancelled
Pending fluid ticks are cancelled, so the server does no work for fluids that would have flowed.
Live toggle command
The ffc command switches fluid flow on or off while the server keeps running.
Permission-based access
Operators at level 3 or higher can use the command, and a permissions plugin can grant the ffc.toggle node to other players.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Embedded 1
Use cases
Who it’s for: Server owners and operators who want to stop fluid flow on a Fabric server, and administrators who manage access through permission nodes.
How it compares
LazyFluids is a server-side only Fabric mod under the MIT License, published for 1.20.1, so it targets an older release than this mod's 1.21.1 build. Cast Away is also server-side only and open source under the MIT License, with files covering 1.19 – 26.3. AntiFog is a client-side only Fabric mod for 1.21.8 under All rights reserved, so it changes the visuals on a player's own client rather than server fluid behavior.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Fluid Flow Controller | Fabric | 1.21.1 | Not published | 2025-10-12 |
| LazyFluids | Fabric | 1.20.1 | Server-side only | 2025-08-27 |
| Cast Away | Fabric | 1.19 – 26.3 | Server-side only | 2026-06-19 |
| AntiFog | Fabric | 1.21.8 | Client-side only | 2025-08-27 |
Questions
Does Fluid Flow Controller need Fabric API?
Can the flow setting change without restarting the server?
Which permissions control the ffc command?
In the catalog
Fluid Flow Controller is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 32,366 mods support Minecraft 1.21.1.
More from sirhephaistos
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What the author says
These commands can be used by server operators (permission level 3 or higher) to enable or disable water and lava flow dynamically without restarting the server. If Luckperms is installed, the permission node ffc.toggle can be used to grant access to these commands. Licensed under the MIT License — feel free to use…
Official listing
- Modrinth page
- modrinth.com/mod/ffc
- Owner
- sirhephaistos
- Published
- 2025-10-12
- Updated on Modrinth
- 2025-10-12
- Facts verified
- 2026-10-15