I put this together from my own time with the game, so if something feels off, bear with me. Keep in mind that versions differ too — I’m writing against 1.0.0.6, and the devs may well change things in later patches.
The old demo star, the water collector, got hit hard. Multiple collectors interfere with each other now: one runs at 100% efficiency, two drop to 80%, three fall to 66% and so on. The Hydra got nerfed as well — base water from it can no longer be filtered into high-quality water. Filter cartridges took a hit too, since they can’t remove microorganisms anymore. You need water purification tablets or a UV lamp for that.
Then a follow-up update quietly rebalanced the purifier, and the early water merchant route works again — zero cost, bulk high-quality water, just with the water purifier instead of the collector. There’s an even better method further down: water reeds cleaning ditch water for 6 nights to make 50L of high-quality water.
First, you need to unlock two water merchant services through Wilde‘s services:
- Water Resource Trading
- Direct Ditch Water Supply
Buy the purifier from the Retired Water Merchant who visits weekly, or from the Doctor at night. On high difficulty the Doctor marks it up 100%, and the Retired Water Merchant marks it up 45%.
Purifier: 1500ml Ditch or Rusty Water With No Modules
With no modules at all, pour 1500ml of ditch water or rusty water into the purifier (that’s 750ml bottle filled twice), and after one night it comes out as 99% high-quality water.
The way the purifier works: the dirtier the input, the more impurities it strips out. I’ve read from other players that when tap water quality swings in the 0.8–0.823 range, you can push 2000ml through overnight and still land on high-quality water. Pushing the limit can backfire though, so 1500ml is the safe number.
On rounding problems: every so often a weird rounding glitch hits. After pouring everything into the large water tank, the water tester shows 99% high-quality down below but 98.99% base water up top. Pouring the water into a small bottle fixes it. If that fails, one water purification tablet rescues the batch. Once you have spare cash, slot a quality module and a performance module into one purifier to avoid this entirely.
Purifier: 2000ml With +51% Performance
Add a performance module at +51% or higher, and 2000ml of ditch or rusty water cleans to high-quality overnight. Go for at least 51 — exactly 50 performance sometimes spits out 98.99% base water, which one water purification tablet can still save.
In the screenshot from my run, a +50% performance purifier cleaning 2L of rusty water landed right on 98.99% and failed, while the same batch through a +51% purifier hit exactly 99.00% high-quality.
Emergency Option: Burn Cartridge Durability for 6L
Take 6L of rusty water, hit it with a UV lamp plus a filter cartridge, run it through a no-module purifier overnight, then drop in 2 water purification tablets the next day and it turns into high-quality water. The catch is brutal cartridge durability loss, so I’d only use this when a water crisis forces an emergency batch to dump.
Water Reeds: 50L in 6 Nights
After unlocking the water merchant services with the old man, you can buy the 20L large bucket from the Doctor and upgrade it to 50L using scrap metal or ingots. Call Wilde and unlock hydroponics through the old man’s services, then buy water reed seeds from the weekly Retired Farmer.
- Fill the 50L bucket with ditch water, put it in the hydroponics machine, and insert water reed seeds.
- After 6 nights of cleaning, add one water purification tablet to the 50L bucket to clear microorganism contamination. A UV lamp works too, if you happen to find one in the Doctor’s random stock.
- Run it through a filter cartridge and it becomes high-quality water. 50L in 6 days is very strong.
- If you lose track of how long the reeds have been cleaning, check with the water quality tester. When chemical contamination shows 0.7% or lower, it’s ready to filter into high-quality water.
Water reeds produce nothing when planted, but don’t worry about losing them — the seed stays behind after planting, so you can loop them for purification indefinitely. Buy a hydroponic reed filter module from the Doctor and it also yields a 250-durability cartridge once the water hyacinth planting finishes.
The reed purification works on percentages: each night strips 28% of each contaminant, but it won’t touch minerals. That means 1L and 50L clean identically. The reeds’ efficiency doesn’t care about module performance or quality either — the only way to boost output is to unlock gene editing and use the DNA machine to strengthen the reeds’ purification genes.
Filtering 3L costs roughly 62 cartridge durability. Turning a full 50L into high-quality water drains about 1033 durability. That’s why I recommend buying the hydroponic reed filter module, adding a bit of performance, and pushing to 9 workload — that way the reeds churn out at least one cartridge every 2 days. And the module description doesn’t say its effect can’t stack, so slotting several means several cartridges.
Pure Water Production
With a purifier at +100 quality you clean water to 99.9%, which lets you produce pure water. Along with the +100 quality, you need one of these:
- At least +1% performance: 6L of high-quality water becomes pure water in one night.
- +100 performance: 15L of high-quality water becomes pure water in one night.
Water Collector Production
The collector got gutted, but you can still buy one and run a “premium” build stuffed with modules. Buy only one — no more. Multiple collectors interfere with each other, and efficiency drops 100% → 80% → 66% as you add them.
- Stack quality to 50 with modules for base water straight out. Hit it with a UV lamp to kill microorganisms, then filter with a cartridge for stable high-quality water. I keep the UV lamp in the toolbox for convenience.
- Stack quality to 100 for direct high-quality water, though I don’t recommend it since it doesn’t reliably turn into pure water.
- Stack quality to 150 for direct pure water. Usually done by pairing one AI chip with a pile of nodes, or four-to-five slot quality/performance learning chips with nodes — very late game.
That covers the early water merchant setup as it stands in this version. If a patch shifts the numbers, adjust accordingly.
