The Filter Stack

The multi-stage purification and emergency treatment rig that can make almost any water source into potable water. The last mile of water sovereignty.

Footprint Compact inline or point-of-use systemsediment, carbon, UV/chemical + solar distillation or boiling backup. Yield Potable water on demand from non-potable sources1–10+ gallons per hour. Cycle Filter changes per schedule; UV bulb annual; solar still as needed; quarterly full test.

Cost tier starterDifficulty weekendLand noneFirst benefit ~1 day

② The Manifest

The parts list. Cores are what you actually need; “if you prefer” opens cheaper, local, or heritage swaps — never budget fallbacks, just other good ways.

Sediment / mechanical filtration

5-micron (or staged 20→5→1) sediment filter or multi-stage housing~$20–80 per housing + filters

First line of defense. Removes dirt, rust, larger particles that clog later stages.

if you prefer… (1)

Cloth or ceramic pre-filter for emergencylowWashable and reusable.

Carbon / chemical adsorption

Activated carbon block or GAC cartridge~$30–100 per cartridge

Removes chlorine, many organics, tastes, odors. Helps with some metals and pesticides.

if you prefer… (1)

Charcoal from hardwood (DIY)very lowCrude but better than nothing in true emergency.

Disinfection (primary)

UV sterilizer (254nm, sized to flow) with pre-filter and flow restrictor~$150–400 for whole-house or point-of-use UV

Kills/inactivates bacteria, viruses, protozoa without chemicals. Requires good pre-filtration and power.

if you prefer… (1)

Chlorine, iodine, or chlorine dioxide tablets (emergency)low per doseChemical backup when UV power unavailable.

Emergency / ultimate backup

Solar still (or multi-stage distillation) + boiling capability~$50–200 for good solar still kit or DIY plans

True Vault-test path. Can produce pure water from almost anything using only sunlight. Slow but completely independent of filters, bulbs, or chemicals.

if you prefer… (1)

Simple pit or box solar still using plastic sheeting$5–20Ultimate low-tech; works but lower yield.

Monitoring and testing

TDS meter, pH strips/meter, occasional coliform test kits~$30–100 for basic kit + occasional lab

You must verify the system is actually working. TDS + biological tests.

Power for active stages

Small dedicated solar panel + battery or direct solar for UV and any small pumps~$100–400 for small solar setup

Filter Stack must run when main power is down. Size for worst-case cloudy period.

if you prefer… (1)

Hand-crank or pedal power for very small flowslow equipmentPossible but tiring for real volume.

③ The Sequence

01Source water assessmentInitial testing + as sources change Know what you are starting with. Rain after good first-flush is easy. Well water may have minerals/bacteria. Surface water is hardest. Test for main threats.
02Assemble the stack in logical order2–6 hrs Sediment → Carbon → UV (or chemical) → final storage. Solar still/boiling is parallel or ultimate backup. Pre-filter everything before UV or still. Label clearly.
03Power and controls2–4 hrs Install dedicated small solar for UV (and pump). Add flow switch so UV only runs when water is flowing. Design for bypass/degraded mode if one stage fails.
04Test the full chain with known-bad water1 day + lab turnaround Run controlled test with contaminated or spiked water. Verify output is safe by test kit or lab. Do this before you ever have to rely on it.
05Establish maintenance and replacement schedule2–4 hrs + ongoing Sediment and carbon have finite capacity. UV bulbs have finite life. Solar stills need cleaning. Calendar + stock of spares. Know how to improvise in long disruption.
06Document degraded-mode operation and the ultimate backup2–4 hrs + periodic drills Write 'if UV fails' and 'if we run out of filters' procedures. Practice the solar still or boiling path. The Stack is only as good as its weakest link and operator knowledge.

⑤ The Echo

Treatment Is the Last Line, Not the First12 min

Why the best water system needs the least treatment. How first-flush, good catchment, and protected storage dramatically reduce the burden on the Filter Stack. Treat the smallest volume of the cleanest water possible.

The Still That Works When Everything Else Is Gone10 min

Solar distillation as the ultimate sovereign water technology. It can produce pure water from seawater, urine, or heavily contaminated sources using only sunlight and simple materials. Slow, but requires no filters, chemicals, electricity, or supply chain.

Well · The Filter Stack · well/filter-stack Offline? Same path on any Ark Mirror.