Rust Water Saturation Guide — How Water Affects Plant Growth
Water is one of the four conditions every Rust plant tracks (alongside Light, Temperature and Soil). Keep saturation high enough that the planter's Conditions display reads "Good" and your plants grow at full speed; let it drop too low and growth stalls. This guide covers how saturation works, common sprinkler-throttle setups, and how the W gene affects consumption.
How water saturation works
Soil saturation is the hidden stat that controls whether your plants are getting enough water. The Conditions display in-game shows water as part of the planter's overall status — when water reads "Good", your plant grows at full speed; when it reads "Bad" the growth rate drops noticeably.
Most farmers aim for sustained ~75-100% saturation. Some long-running community guides argue an even narrower 65-85% band is optimal because over-watering may cause minor growth penalties — but Facepunch hasn't published exact thresholds, and the planter's Conditions display is the authoritative source: if it reads Good, you're fine.
Bottom line: don't let saturation drop low enough that the conditions read Bad, and don't waste sprinkler resources blasting more water than the planter can hold. Tune by what the in-game display actually says.
Sprinkler throttle setups
A typical Rust farming sprinkler setup keeps water topped up without wasting resources:
- One sprinkler per two planters, sprinkler centred between them — common community setup that keeps saturation in the high range without per-planter sprinkler cost.
- Throttle with an Electrical Branch: a Branch upstream of your sprinkler set lowers passthrough and leaves the rest of the budget for sensors or lights.
- Smart Switch + timer: cycles sprinklers on/off so saturation averages out across the cycle.
Whichever approach you pick, watch the Conditions display on a few representative planters. If water reads Good consistently, your setup is working — independent of the exact saturation percentage.
How the W gene changes the math
Each W gene in a plant's genome increases water consumption. A clone with two W genes drinks roughly 50% more water than a clone with zero — meaning the saturation falls faster and your sprinkler-to-planter ratio shifts.
This is one reason why W is universally a 'bad' gene to keep. Even if your sprinkler setup is dialled in for normal clones, a single W-heavy clone in the planter will pull the saturation lower for everyone else.
If you've inherited a W-heavy clone and can't replace it yet, the workaround is to add a second sprinkler at low throttle, or move that planter to its own water-source line.
Water source throughput
Your water source has to keep up with the sprinkler's draw or saturation falls. Throughput at the source, in litres per minute:
- Water Catcher (small) — ~3 L/min in moderate rain, ~0 in dry weather.
- Water Catcher (large) — ~6 L/min in moderate rain, ~12 in heavy rain.
- Water Pump (powered) — ~30 L/min, but needs power and must be near water.
- Pump Jack — pulls from underground; consistent but power-heavy.
For a 4-planter farm, two large catchers usually cover all sprinklers in normal weather. For an 8-planter operation, you'll want a powered pump or four catchers minimum.
Common mistakes
- Maxing the sprinkler output assuming more = better. It's the single biggest mistake new farmers make.
- Ignoring rain cycles. If your only source is catchers and the wipe rolls into a dry stretch, your saturation craters and clones stop growing.
- Mixing W-heavy and W-free clones in the same planter. Their water needs differ, and the average saturation works for neither.
- Stacking too many planters per pump. Eight planters on one Water Pump line is fine; sixteen will starve under sprinkler load.