- Probably Stolen water quality has four tiers: rust, base, high-quality, and pure water.
- UV lamps only kill microbes; filters remove organic waste, minerals, and physical contaminants.
- A water purifier at 100% quality reaches 99.9% purity for pure water overnight.
- A moisture farm at 150% quality produces pure water daily without purification.
- Spring water bottles attract a water stockpiler buyer worth 500+ credits from day 14.
Water Quality Tiers Explained
Water quality is the core of Probably Stolen's survival economy. Every water source in the game carries contaminants, and each purification tool targets a specific category. Understanding this system is the difference between selling cheap rust water and banking credits on pure water.
The game runs on four quality tiers, and each tool—UV lamp, water filter, purifier machine, or living plants—only handles part of the job. Mix them correctly and rust water from your faucet becomes high-value pure water.
Video Highlights:
- Two easiest high-quality water methods: water purifier overnight, or UV lamp plus filter pitcher
- UV lamps remove microbes only; filters remove organic waste, minerals, and physical contaminants
- Water purifier at 100% quality achieves 99.9% pure water
- Moisture farm at 150% quality makes pure water daily
- Spring water bottles trigger a water stockpiler buyer from day 14
| Tier | Purity | How to Obtain | Typical Use |
|---|---|---|---|
| Rust Water | Lowest | Faucet tap by default | Raw input for purification |
| Base Water | Mid | Filter rust water or buy from scavengers | Intermediate step |
| High-Quality Water | High | UV + filter combo, purifier overnight, tilapia, hydra weed | Selling, drinking |
| Pure Water | 99.9% | Purifier at 100% quality, moisture farm at 150% | Top sale price |
Use the aqua scan regularly to check contamination levels. Each scan reveals exactly which contaminants remain, so you know which tool to apply next instead of guessing.
Purification Tools and What They Target
The key rule of Probably Stolen water quality: no single tool does everything. Each purification method has a specific target set, modeled after real-world filtration pros and cons.
UV Lamp
- Removes microbes only
- Works instantly on bottles
- Does nothing to minerals or waste
Water Filter
- Removes organic waste, minerals, physical contaminants
- Leaves microbes untouched
- Pair with UV lamp for full cleanup
Water Purifier
- Removes all contaminants
- Works overnight on stored water
- Max purity 99.9% at 100% machine quality
Gutter Tilapia
- Cleans water in recirculating aquaculture
- More fish means faster cleaning
- Passive, slow but reliable
Hydra Weed
- Found in the old hydroponic system
- Cleans water slightly each growth cycle
- Repeated grows reach high quality
Moisture Farm
- Generates water from scratch
- 55% quality makes base water
- 150% quality makes pure water daily
| Tool | Contaminants Removed | Speed | Max Quality |
|---|---|---|---|
| UV Lamp | Microbes | Instant | Base → High-Quality (with filter) |
| Water Filter | Organic, mineral, physical | Instant pour | Base → High-Quality (with UV) |
| Water Purifier | All | Overnight | 99.9% pure |
| Gutter Tilapia | Gradual cleanup | Days | High-Quality |
| Hydra Weed | Gradual cleanup | Multiple grows | High-Quality |
| Moisture Farm | N/A (generates water) | Daily output | Pure at 150% quality |
Purifying with UV lamp and filter works reliably on base water purchased from sellers because their contaminant mixture suits this combination. If you make your own base water, the contaminant mix may differ depending on your path, and the combo may not be enough.
Step-by-Step: Making Pure Water
Pure water is the top money-maker, and there are exactly two reliable routes: the water purifier machine and the moisture farm. Both depend on pushing machine quality to specific thresholds.
Collect and Pre-Filter Your Water
Start with rust water from the faucet or base water from a scavenger. Run it through a filter pitcher (with a hydro reed filter installed) to strip organic waste, minerals, and physical contaminants.
Kill Microbes with a UV Lamp
Apply the UV lamp to the bottle to eliminate microbes. This step plus the filter converts purchased base water into high-quality water. Scan to confirm.
Upgrade Your Machine Quality
For the purifier route, reach 100% machine quality or higher. For the moisture farm route, install refinement modules until quality hits 150%. Expansion kits (up to two) open extra module slots for quality bonuses.
Purify Overnight or Harvest Daily
Pour high-quality water into the purifier jug—it hits 99.9% purity overnight. With a moisture farm at 150%, pure water (hundreds of ml per day) generates automatically.
Store and Sell
Transfer pure water into water tanks (up to 50,000 ml capacity) and place two spring water bottles in your shop to attract the water stockpiler buyer.
The thresholds are strict: a purifier below 100% quality cannot hit 99.9% purity, and a moisture farm below 150% only produces base or high-quality water. Hunt for modules with large quality bonuses before committing to mass production.
Selling Water and Buyer Setup
Water is one of the steadiest income streams in the game, but the buyer you attract depends on the value of water displayed in your shop.
| Display Setup | Buyer Attracted | Approx. Earnings |
|---|---|---|
| Two spring water bottles | Water stockpiler | 500+ credits from day 14 |
| Spring water + high-quality standard bottle | Water stockpiler | Combined value over 365 |
| Random water bottles | Low-level buyers | Inconsistent income |
Key selling facts:
- Spring water bottles have very high base value and reliably trigger the water stockpiler, a wealthy buyer who purchases all your high-quality or pure water.
- One spring bottle comes from Natalia's questline; the other can drop from random crates.
- If you cannot find a second spring bottle, a high-quality standard bottle works—the combined display value just needs to exceed 365.
As production scales, storage becomes a bottleneck. Upgrade toward a 50,000 ml water tank so overnight purifier batches never go to waste.
Water Production Checklist
Work through these milestones in order. Each one unlocks the next tier of water-based income.
Water Quality Milestones:
- Acquire a water filter pitcher and UV lamp
- Produce first batch of high-quality water
- Raise water purifier machine quality to 100%
- Craft first jug of pure water (99.9% purity)
- Install two expansion kits for extra module slots
- Upgrade to a 50,000 ml water tank
- Display two spring water bottles for the stockpiler buyer
Press E or Q to rotate machines and right-click to flip them. Use efficiency modules to cut energy costs, or performance modules to increase purification output per night.
FAQ
Q: Why won't my UV lamp and filter make high-quality water?
The UV lamp only removes microbes, and the filter only removes organic waste, minerals, and physical contaminants. You need both applied to the same water. Also, this combo works best on purchased base water; homemade base water may carry a contaminant mix that requires a purifier machine instead.
Q: What are the only two ways to make pure water in Probably Stolen?
Use a water purifier machine raised to 100% quality or higher, which purifies water to 99.9% overnight, or run a moisture farm at 150% quality or above, which produces pure water daily without needing input water.
Q: How do I increase machine quality to reach pure water thresholds?
Install modules with large quality bonuses, such as refinement modules in the moisture farm. Use up to two expansion kits per machine to unlock additional module bays for more quality, efficiency, or performance modules.
Q: How do I attract the water stockpiler buyer?
Display two bottles of spring water in your shop. From around day 14 onward, this reliably spawns the water stockpiler, who buys all your high-quality or pure water for 500+ credits. A high-quality standard bottle can substitute for a second spring bottle if the combined value exceeds 365.