Mastering water trading is hands-down one of the fastest ways to build your bank account in Probably Stolen. You will start with basic filtration gear before upgrading to chemical purifiers and pulling in high-spending customers.
It is easy to waste valuable filters on heavily contaminated liquid early on if you do not know how microbes work. This guide walks you through every step from testing your first bottle to processing stubborn Rustwater.
Make sure you hold onto your starting 6L jug before you begin messing with batch filtration. You will need it for processing larger amounts of liquid without running out of containers.
How to Sell Water
Water trading starts with checking your stock, setting up bottles for sale, and displaying water where customers can see it. Your earnings depend on the water purity, the amount you have available, and the customers your shop attracts.
Keep your starting 6L jug. You will need it for processing larger amounts of water, and replacing it can be difficult early in the game.
How to Test Water Purity
Your Water Trader starting equipment is testing strips. Open the container holding the strips, then drag one into a container filled with water. The test reveals the water purity percentage, which determines its quality and selling price.
Testing every small bottle can waste strips. Instead, combine water in a larger container, such as your 6L jug, and test the combined batch when appropriate.
Use testing strips whenever you buy water from a merchant. Sellers can mislabel their stock, and the water appearance can sometimes reveal a problem before you spend your money.
- Basewater: Check the label and test the purity before buying.
- Ghostwater: Darker-looking water can indicate poor quality. If the seller labels it as Basewater, test it before accepting the deal.
- Rustwater and Gutterflow: These require more work than ordinary water and are not good choices for your first filtration setup.
If you catch a seller mislabeling water, confront them. Exposing their scam can help you get a lower price.
How to Buy Water Without Getting Scammed
Buying water can help you build your trading business before you have a steady supply of your own. However, do not spend your early money on large quantities of untested water.
Follow these rules when buying stock:
- Test bottles with your testing strips whenever possible.
- Check suspiciously dark water before paying the listed price.
- Avoid buying large quantities of 2L bottles without checking their purity.
- Save your money for equipment that can improve your water supply and processing speed.
A cheap bottle is not a bargain if its contamination makes it difficult to turn into high-quality water.
Basic Water Trading Filtration
Your starting equipment lets you process ordinary contaminated water. However, the old demo method of using a purification pill and a pitcher filter does not always produce high-quality water in the full game.
The most important change is that water filters no longer remove microbial contamination. You need to treat microbes with purification tablets or a UV lamp before relying on filtration.
Basic filtration steps
- Put the water you want to process into a suitable container.
- Treat microbial contamination with a Water Purification Tablet or UV Lamp.
- Attach a Water Filter to your water pitcher.
- Pour the treated water into the pitcher.
- Collect the filtered water in another container.
- Test the result before selling it as high-quality water.
Check the filter durability if the result is worse than expected. A filter at 0/400 durability needs replacing before you process the water again.
Keep one or two spare filters in storage. You should also avoid filling your inventory with too many small water bottles because they take up space quickly.
Why filtration sometimes fails
A working filter does not guarantee high-quality water. There are two common reasons for a poor result:
- Microbial contamination remains: Use a Water Purification Tablet or UV Lamp before filtering.
- Chemical or heavy metal contamination is too high: Ordinary filters cannot remove enough of these contaminants to reach the high-quality threshold.
High-quality water requires at least 99% purity. Water that tests at 98–99% may need additional treatment or dilution with higher-purity water.
Intermediate Water Trading Tablets and Purifiers
Once you start processing larger amounts of water, replacing filters will become a regular expense. Water Purification Tablets, UV Lamps, and purifier machines can reduce contamination before the water reaches your pitcher.
Here is what each piece of equipment does:
| Equipment | Main use |
|---|---|
| Water Purification Tablet | Removes microbial contamination and reduces chemical contamination to around 0.71%. |
| UV Lamp | Removes microbial contamination. It can also fit inside a water pitcher. |
| HydraTech Water Purifier | Removes contaminants up to the base water quality and can help with water that ordinary filtration struggles to process. |
| Water Purifier machine | Treats water over time, gradually reducing contamination. |
The standard Water Purifier machine is especially useful when you want to process water overnight instead of repeatedly working with a pitcher.
How to use the Water Purifier machine
You will need:
- A Water Purifier machine.
- Batteries to power the machine.
- Water Purification Tablets.
- A 2L bottle or your starting 6L jug.
- Water to process.
You can purchase the machine from the retired merchant for 345 Credits or from Doc Jackson for 375 Credits. You can also use the battery from your bottle printer if you need one to get started.
Follow these steps:
- Add a Water Purification Tablet to the water. I recommend one tablet for a 2L bottle or two for a 6L jug.
- If you own a UV Lamp, use it to remove microbial contamination before machine treatment.
- Place the water container inside the powered Water Purifier.
- Leave a 2L bottle in the machine for one or two nights. A 6L jug may need around three nights.
- Remove the water and process it through a pitcher with a Water Filter.
- Test the finished water before putting it up for sale.
If the result is still Basewater, try another tablet or UV treatment. You can also leave the water in the purifier for another night and test it again.
Advanced Water Trading Dilution
Dilution helps you increase the amount of high-quality water you can sell. You combine water that has excess purity with lower-quality water, bringing the final mixture closer to the 99% high-quality threshold.
For example, mixing equal amounts of water at 99.5% and 98.5% purity gives you 2L of water at approximately 99% purity.
The same principle works with different volumes, but the final percentage depends on the purity and amount of each batch.
How to dilute water correctly
- Test your high-quality water and note its purity.
- Test the lower-quality water you want to mix with it.
- Combine the two amounts in a suitable container.
- Test the mixture again to confirm that it still meets the high-quality threshold.
Do not expect that adding any amount of high-quality water will fix a contaminated batch. If the lower-quality water contains too much chemical or heavy metal contamination, you may need to process it further first.
Pure water can also be useful for dilution because it allows you to increase the volume of water while maintaining a high final purity.
Attracting Upper-Level Water Buyers
Upper-level buyers can spend more money than ordinary customers, making them valuable once you have enough stock to display.
To attract upper-level water buyers, keep at least 350 Credits worth of water on display. You can also attract them by labeling most of the displayed water as Pure Water.
A full 6L jug of high-quality water is one way to build up your display value. I also recommend keeping Springwater available rather than selling it immediately, as it may help attract higher-level water merchants.
Keep these additional details in mind:
- Upper-level buyers do not appear during the first two weeks.
- Store appearance perks can increase the amount these buyers are willing to spend.
- Discounts can also increase their available budget.
- At 20 Upper Level Reputation, the water hoarders start giving a 15% tip.
Upper-level water buyers will visit your shop when you meet either of these conditions: display water worth at least 350 Credits or label most of your displayed water as Pure Water.
Expert Water Trading Chemical and Heavy Metal Contamination
Some water remains stuck at Basewater quality even after you use tablets and filters correctly. The reason may be chemical or heavy metal contamination that ordinary filters cannot remove.
An Aquascan device lets you inspect the types of contamination in your water. You can get one at Doc Jackson shop when a household goods surplus reduces its price.
Use the Aquascan when repeated filtration fails to improve your water. If chemical and heavy metal contamination remain too high, you will need additional treatment rather than more passes through the same filter.
Dilution can help when the remaining contamination is low enough, but heavily contaminated water requires a more involved process.
How to Process Rustwater into High-Quality Water
Rustwater is more difficult to process than ordinary water. You need to reduce its contamination before relying on your Water Filter.
Step 1 Treat the water
Start with a Water Purification Tablet to remove microbial contamination and reduce chemical contamination. Use one tablet for a full jug.
Step 2 Reduce microbial contamination
If you skipped the tablet, use a UV Lamp to remove microbial contamination before moving on.
You can also use the HydraTech Water Purifier. This machine can improve some water that would otherwise be difficult to process into high-quality water.
Step 3 Reduce chemical and heavy metal contamination
You can also use the Sewer Tilapia to reduce chemical and heavy metal contamination. More fish can speed up the process, and the fish can survive without a filter in their tank.
However, Sewer Tilapia produce organic waste, which can add contamination that a water filter can remove. Check the water after treatment rather than assuming the fish have made it ready for sale.
Step 4 Filter the water
Once chemical and heavy metal contamination have dropped enough, move the water into your pitcher and run it through a Water Filter.
Test the final result. If the water is still below high-quality purity, continue treatment or consider mixing it with higher-purity water.
Step 5 Use dilution to save time
If you already have high-quality water available, dilution may reduce the amount of additional treatment your Rustwater needs. Calculate the mixture carefully and test it before selling it.
This can be useful when the remaining contamination is low, but it will not replace proper treatment for heavily contaminated water.
Optional How to Scam People
Probably Stolen also allows you to mislabel water to show it as more valuable than it really is. This is a risky way to earn Credits because customers can test your stock.
You can change the labels from basewater to high-quality, such as Ghostwater or Basewater, to higher-quality categories using a labeler. However, some buyers bring their own testing kits, and customers who spot a scam may confront you.
I have also faced consequences after selling around 100L of mislabeled water.
If you choose to experiment with this mechanic, remember that the label does not improve the actual water purity. It only changes what the customer sees.