Make Pure Water using rat feces

Goal: turn a dirty water batch into the in-game Pure Water grade. The route is unusual: use feces on the water container until the batch falls below the portable purifier’s 98% cutoff, purify it, then use UV and a suitable pitcher filter. Pure Water is a grade; it does not promise 100% purity or a profit.

You need water to treat, feces, a HydraTech Micro Water Purifier, a UV Lamp, a Water Pitcher with a usable Water Filter, an empty receiving bottle, and an AquaScan or testing strips. The rat-raising guide covers keeping a supply of rats.

1. 
   1. Scan the batch

   Check purity and contaminants before choosing a route.

2. 
   2. Leave room and lower purity

   Use feces until the batch is below the 98% purifier cutoff.

3. 
   3. Use the portable purifier

   Run HydraTech before UV and pitcher filtration.

4. 
   4. Treat microbes with UV

   The UV Lamp converts microbes into water.

5. 
   5. Filter into the pitcher

   Fit a usable Water Filter, then pour treated water into the pitcher.

6. 
   6. Test and decide whether to repeat

   Check the grade and readings; repeat the full cycle only if the cost makes sense.

1. Check the batch and prepare capacity

Use AquaScan to identify the starting contaminants; testing strips show purity but do not replace a detailed contaminant scan. If the batch is already Pure Water, stop. If ordinary filtration can bring it to the target grade, use that simpler route. This method is for a batch that needs the portable purifier but is too pure for it to activate. Note any heavy metals or chemical contamination, since the ordinary pitcher filter will not remove either.

Make room in the batch before adding feces. Each item adds liquid volume as well as contaminants:

Feces size	Organic waste	Debris	Microbes	Total added
Animal Feces (Small)	10 ml	1 ml	4 ml	15 ml
Animal Feces	20 ml	2 ml	8 ml	30 ml
Animal Feces (Large)	40 ml	4 ml	16 ml	60 ml

2. Lower purity below the purifier cutoff

Start by using one feces item on the water container, then recheck purity; add more until the batch is below 98%. Larger additions can remove more stubborn contamination per purifier use, but require more headroom and filter work, so there is no fixed best count. Feces add no water, heavy metals or chemical contaminants. They increase the removable share of the batch, so the purifier’s proportional reduction leaves less of those stubborn contaminants behind; UV and filtering then remove the microbes and eligible waste added with the feces. Leave capacity for the feces volume. The purifier keeps total volume unchanged.

3. Run the portable purifier

Run the portable purifier before using the UV Lamp or pitcher. It keeps the batch volume and reduces the non-water contaminants proportionally. It charges 1 durability per started 100 ml of batch and may refuse a batch if it cannot pay the full cost.

4. Treat microbes with the UV Lamp

Use the UV Lamp after the portable purifier. It converts microbes into water.

5. Filter the treated water into the pitcher

Install a Water Filter that still has durability in the Water Pitcher, then pour the UV-treated water into the pitcher so the fitted filter treats it. Transfer the resulting water from the pitcher into the empty receiving bottle, and keep the pitcher’s capacity in mind. UV and the ordinary filter handle different contaminants; the filter can remove eligible organic waste, debris and minerals, but it will not remove heavy metals or chemical contamination.

6. Test the result and decide whether to repeat

Check both the displayed grade and contaminant readings after the full cycle. If the batch is still below Pure Water and heavy metals or chemical contamination remain, do not keep filtering alone: compare the durability and cost, then repeat from adding feces, through the purifier and UV, and filter again. Recheck after every full cycle; stop when it reaches the target or the cost no longer makes sense.

Example batch

• After adding feces: 82.66%
• After portable purification: 98.00%
• After UV and pitcher filtration: 99.92% — Pure Water

One recorded batch; the recipe and final purity vary with the starting water and equipment.

Troubleshooting

• The portable purifier does nothing: purity may be 98% or higher, or its durability may be too low for the batch.
• The batch will not fit: remove some water or use a larger-capacity setup before adding feces; the feces itself adds volume.
• The filter wears down without fixing the reading: check that it is usable and has durability. Filters only remove eligible contaminants within their pore and limit rules.
• The reading plateaus at heavy metals or chemical contamination: ordinary Water Filters do not remove those contaminants.
• You saw advice to use Kotton Fabric: do not use it for this job. Its item description says the material is too coarse for water purification.

For contaminant behavior and purifier details, see the water and purifier reference. For other water routes, see water trading.

Sources

Probably Stolen demo 049-Rev3-L game files; Steam community discussion of the rat-feces purification route. Example batch: from 及时邢乐’s August 16, 2026 Bilibili video, 《深空当铺》如何制作纯水，老鼠屎净水教学 (accessed October 19, 2026).