Probably Stolen Water Guide: How to Purify Water and Reach 100%

Quick answer

Tablets and a filter take most water to Basewater. To go further you need the Water Purifier, which tops out at 99% without Quality modules. Pure Water needs at least a +100 Quality bonus. Always test before you sell, because mislabeled water is your liability.

On this page

Check your batch

The Water Calculator tells you the grade, your purifier's limit and how far you can stretch a batch by blending.

Water grades

Grade	Purity	Notes
Pure Water	99.9%+	Very expensive; hospitals and labs
High-Quality	99 to 99.9%	Upper Levels standard
Basewater	98 to 99%	Lower Levels standard
Ghostwater	96 to 98%	Looks clean, so you can't judge it by eye
Rustwater	90 to 96%	Dangerous and visible by eye
Gutterflow	Under 90%	Toxic and visible by eye

Why won't my tablets or filter work?

This is one of the most common questions in the forums. Each tool only fixes some contaminants.

Tool	What it does	Limit
Purification Tablet	Removes most microbes and some chemicals	Chemicals first, then microbes; dirty water needs several
Water Filter	Removes impurities, microplastics and organic waste	Ineffective above a certain purity, and wears out
UV Lamp	Kills bacteria and other microbes	Doesn't replace tablets
HydraTech Micro Purifier	Raises a container to Basewater	Loses 1 durability per 100 mL
Water Purifier machine	Removes contaminants overnight	Capped at 99% without Quality modules
Kotton Fabric	Too coarse for water	Don't use it here

The Steam guide's testing shows heavy metal and chemical contaminants are what keep water stuck at Basewater. Filters can't take those out, so you need the purifier, more tablets or a dilution.

How to reach High-Quality

For Rustwater, one player guide uses this routine:

Add tablets: 1 for a 2 L bottle, 2 for a 6 L jug.
Optionally use a UV lamp.
Leave it in the purifier overnight: 1 to 2 nights for 2 L, 3 nights for 6 L.
Pour it through the filter pitcher.
Test it, and repeat a step if it's still Basewater.

Save the purifier for Gutterflow and for the final push to High-Quality. Tablets and a filter handle the rest more cheaply. The purifier removes minerals, chemicals and heavy metals last, so progress slows near the top.

How to get Pure Water

You need Quality modules in the purifier. Without them the machine stops at 99%.

Quality bonus	Max purity
None	99%
+15	99.15%
+25	99.35%
+50	99.65%
+75	99.8%
+100	99.9%
+200	100%

Aim for at least +100, and check the Max Purity tooltip before buying more modules. In one test, a purifier at 103% quality turned a 6 L jug of 99.00% water into 99.90% Pure Water in one night.

Where to get water and containers

Check this before you buy equipment. One player lost a run holding empty bottles and no water.

Water Trading in Wild's Network costs 300 favor and gives you a starter kit, but no purifier machine.
Gutterflow On Tap costs 250 favor. It's unlimited, and its purity changes daily.
Rustwater On Tap costs 350 favor.
Moisture Farm costs 350 credits since patch 1.0.0.2, and you supply the container. Guides report about 850 mL of Ghostwater a night from one farm, and 1,360 mL from two, so output falls as you add more.
The Water Purifier machine comes from Dr. Jackson while you don't own one, or the Retired Water Merchant on Wednesdays. Its base value is 250 since patch 1.0.0.5.

Blending

Water above your target grade can stretch cheaper water. 1 L at 99.5% plus 1 L at 98.5% averages 99%. The same guide warns about losing roughly 0.25% per dilution step, so aim a little high and test.

Who buys what

Upper-class buyers don't appear in the first two weeks, and they want a displayed value of about 300 to 350 credits. A full 6 L jug of High-Quality water can do it.
Some Lower Level citizens and Scavengers won't buy Pure Water.
Bulk buyers usually carry a testing kit. Scavengers usually can't afford one, and tourists and Upper Level citizens rarely test.
BloomBerry wine needs High-Quality water or Basewater, because fermentation needs minerals that Pure Water lacks.

Relabeling has a cost

Selling low-grade water as something better can catch up with you. A customer poisoned by your water can come back for you, and players report that the relabeling trick was weakened in 1.0.