The UV Lamp in the game Probably Stolen is a useful tool for improving contaminated water, particularly when microbes are preventing you from reaching a higher purity grade. However, where you use the lamp may affect how much water you recover, making the difference between a bottle and a pitcher surprisingly important.
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How to Use the UV Lamp
UV Lamp in a Bottle vs. Pitcher
What Does the UV Lamp Remove?
Using UV Light for Water Purification
Why Your Water Isn't Getting Purer
How to Use the UV Lamp in Probably Stolen
To use the UV Lamp, apply it directly to a bottle or jug containing contaminated water. The lamp treats microbial contamination, helping improve the water's purity without needing to rely entirely on purification tablets.
- Fill a bottle or jug with the water you want to treat.
- Apply the UV Lamp directly to that container rather than installing it in a Water Pitcher.
- Allow the lamp to treat the microbial contamination.
- Use a Water Testing Strip afterward to check the updated purity.
- If other contaminants remain, continue treatment using the appropriate purification equipment.
The UV Lamp is particularly useful when microbes are the remaining obstacle to improving your water grade.
In the current water trading system, ordinary Water Filters don't remove microbes. That gives the UV Lamp a distinct purpose alongside filters, tablets, and purification machines.
Importantly, UV Light doesn't automatically turn every type of dirty water into High-Quality or Pure Water. Other contaminants may still need separate treatment.
Should You Put the UV Lamp in a Water Pitcher?
If your goal is to preserve as much water as possible, using the UV Lamp directly on a bottle or jug is the safer approach.
Players have identified a potentially important difference in how the lamp handles microbes depending on where it's installed.
| UV Lamp Placement | Reported Effect |
|---|---|
| Directly on a Bottle or Jug | Microbial contamination is converted into water, helping preserve liquid volume. |
| Installed in a Water Pitcher | Microbial contamination is removed without being converted into additional water. |
This distinction comes from player testing and has been corroborated by another player observing the same behavior. It hasn't been established whether the difference is intentional or a bug.
Why Does UV Lamp Placement Matter?
Water purity and water quantity aren't the same thing.
Two containers can end up with similarly clean water, but the container that retains more liquid gives you more usable water to bottle, store, or sell.
If microbes are converted into water instead of simply discarded, the treatment can potentially improve both purity and usable yield.
That makes direct application particularly interesting when processing larger volumes or trying to maximize how much high-grade water you recover from limited supplies.
I'd avoid putting the UV Lamp in a pitcher when water preservation is the priority, at least until this behavior is clarified or changed.
What Contaminants Does the UV Lamp Remove?
The UV Lamp targets microbes. It's not a replacement for the rest of your water purification equipment.
Different contamination types require different treatments:
| Contaminant | UV Lamp Effect |
|---|---|
| Microbes | Treats microbial contamination |
| Organic Waste | Requires other treatment |
| Large Particles | Requires filtration |
| Chemical Contaminants | Requires other treatment |
| Heavy Metals | Requires other treatment |
This is why using the UV Lamp on heavily contaminated water may not produce a dramatic change in the displayed quality grade.
For example, Rustwater can contain several types of contamination. Eliminating microbes doesn't also eliminate the chemicals or heavy metals that may be keeping its purity low.
When Should You Use UV Light for Water Purification?
The biggest advantage of the UV Lamp is that it gives you a dedicated way to handle microbial contamination while preserving purification tablets for situations where their broader effects are useful.
Purification tablets can treat microbes and reduce chemical contamination, while the UV Lamp specifically addresses microbes.
UV Lamp or Water Purification Tablets?
If microbes are the main problem, the UV Lamp is a logical choice because you don't need to use a tablet just to address that contamination type.
If chemicals are also preventing the water from improving, tablets may still be necessary.
One practical approach is to examine the contamination before deciding which tool to use, rather than automatically putting a tablet into every container.
An AquaScan can help identify which contaminants remain, while a Water Testing Strip checks the water's overall purity.
Can the UV Lamp Help Make Pure Water?
Yes, but only as part of a broader purification process when the water contains other impurities.
One unusual player-tested method starts with water contaminated by rat waste. This produces a mixture containing microbes, organic material, and particles.
The UV Lamp handles the microbial portion, after which filters and further treatment can address the remaining contamination. Players have reported obtaining 100% pure water through this approach.
However, this is an experimental method rather than a guaranteed production recipe for every game version. The important UV Lamp takeaway is that microbes can be treated separately from the other impurities in the mixture.
For more on the different water grades and purification methods, see our Probably Stolen Water Purification Guide.
Why Isn't the UV Lamp Making Your Water Purer?
If you've used the UV Lamp but the water still isn't reaching your target grade, that doesn't necessarily mean the lamp failed.
Other Contaminants Are Still Present
The most common explanation is that microbes weren't the only problem.
Water containing chemicals, heavy metals, organic waste, or physical particles still needs the appropriate treatment. The UV Lamp doesn't address those impurities.
You're Checking Only the Water Grade
Water grades represent purity ranges, so removing contamination won't always move a container into a different grade.
If you're trying to diagnose the lamp's effect, compare the water's actual purity percentage and contaminant breakdown rather than relying solely on whether the label changed.
You're Losing Water During Pitcher Treatment
If the water appears cleaner but you're recovering less of it than expected, check whether the UV Lamp is installed in a pitcher.
Based on player observations, direct bottle or jug treatment can preserve more liquid by converting microbes into water instead of simply removing them.
You can test this distinction yourself by comparing two equivalent containers, treating one directly and passing the other through a pitcher equipped with the lamp. Compare the remaining volume and purity afterward.
For regular water trading, I'd use the UV Lamp directly on containers when treating microbes, then rely on filters, tablets, or other equipment for whatever contamination remains. That keeps each tool focused on the job it actually performs while helping avoid unnecessary water loss.
