Water Processing Report

1. Purpose

The camera operates in remote locations with no municipal water or drainage. This document specifies a self-contained three-circuit water system that:

• Stores sufficient clean water for 9–14 full-size prints between resupply runs on fresh Blue alone (~14 prints once Brown wash-2 recycling is counted — see §below)
• Recycles used wash water through a three-stage filter train, extending usable supply by approximately 40%
• Contains all waste water in a closed, transportable IBC for proper off-site disposal
• Runs entirely on 12V DC, compatible with a solar/battery off-grid power system

Three circuits:

Circuit	Color code	Purpose	Storage
Blue	Blue — clean	Fresh water supply for processing	2× 1,000L IBC totes (1,800L working fill total — 900L each), stacked side-by-side
Brown	Brown — used	Collected wash water; filtered and recycled back to Blue	1× 1,000L IBC tote, stacked below Blue IBCs
Black	Black — waste	Heavily contaminated water; sealed IBC for off-site disposal	1× 1,000L IBC tote, stacked below Blue IBCs

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2. Cyanotype Wash Water — Chemistry and Constraints

What is in the wash water?

When a cyanotype print is washed, the water picks up:

Compound	Source	Notes
Ferric ammonium citrate (FAC)	Unexposed sensitizer	Water-soluble, pale yellow; low toxicity
Potassium ferricyanide	Sensitizer component	Water-soluble, yellow-orange; low acute toxicity
Prussian blue particles	Exposed image pigment wash-off	Fine blue solid particles, ~1–10 micron
Iron(III) compounds	Oxidation products	Color the water blue-gray

pH: Wash water starts slightly acidic to neutral (pH 6–7) and may drift alkaline as iron compounds accumulate. Alkaline conditions (pH >8) must be avoided — they accelerate slow breakdown of ferricyanide to ferrocyanide and trace cyanide ions.

Environmental note: Cyanotype wash water is low-toxicity and is generally accepted to the municipal sewer in dilute volumes (Photrio forum consensus; corroborated by Safety Data Sheets for FAC and potassium ferricyanide). However, for remote field use with no sewer access, it must be contained and transported for disposal. Do not pour on soil or into waterways.

Source: Photrio — Cyanotype wash water composition · Ask MetaFilter — Disposing of cyanotyping water

What filtration can and cannot do

A sediment + activated carbon filter train will: - Remove Prussian blue particle load (sediment stages) - Reduce some dissolved organics and iron-complex color (carbon stage) - Restore water to a usable secondary-wash quality after 1–3 passes

It will not: - Completely restore water to fresh-water quality - Remove dissolved iron salts fully without iron-specific media - Make the water safe for discharge to ground

Rule of thumb: Recycled Brown water may be reused for the first wash of each print (roughest wash). The final wash must always use Blue (clean) water to avoid re-depositing iron compounds onto the print. After 3 recycle passes, water goes to Black.

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3. Water Volume Calculations

Per-print water requirement

Processing a ~106 sq ft print in the processing tray (4459 × 2,200mm), flooded to 6mm (¼ inch) depth:

Volume per flood = 106 sq ft × (6mm / 304.8) = 106 × 0.0197 ft = 2.09 cu ft
                 = 2.09 × 7.48 = 15.6 gallons ≈ 16 gallons per wash cycle

Wash cycle	Water source	Volume	Drain to
Wash 1 — 5 min	Blue (clean)	16 gal	Brown tank
Wash 2 — 5 min	Brown (recycled)	16 gal	Brown tank
Wash 3 — 5 min	Blue (clean)	16 gal	Brown tank → Black if >3 recycles
Total per print		~32 gal net Blue consumed

Storage capacity vs. print count

Scenario	Blue consumed per print	Prints from 476 gal Blue	Brown recycled
No recycling	48 gal (3 × 16)	~10 prints	0
With recycling (wash 2 from Brown)	32 gal (2 × 16)	~14 prints	~224 gal reused
Brown recycle limit (3 passes)	—	—	166 gal max before going to Black

~14 prints per resupply run — 1,800L Blue supply (2× 900L) with Brown recycling for wash 2.

Water balance — recovered vs. consumed. Of the 1,800L Blue supply, a 14-print run processes ~1,690L (leaving ~110L of dregs, under one print): ~1,260L is recovered into the collection totes (Brown + Waste, ~630L each at their working fill) and ~434L (~31L per print, ~17% of the ~182L gross washed per print) is open-process loss — water carried out in the wet prints (each full-plane muslin sheet, ~10.7 m², leaves saturated to dry), evaporation from the open spray-wash tray, and unrecovered residual (tray-surface film, the sump dead-volume below the P-04 pickup, hose/manifold hold-up). This loss is why two 630L collection totes balance the supply — they are sized for the recovered fraction, not full throughput. (The weight report carries the same ~1,260L recovered figure for its exhausted-state transport mass — 4,590 kg, ~540 kg below the loaded state.)

Extending capacity beyond 14 prints

Maximizing the initial load. The standard 900L-per-tote fill (1,800L → 14 prints) leaves a little residue in each 1,000L tote; topping toward the ~950–1,000L tote limit (~1,900–2,000L) buys ~1–2 more prints (~15–16), transport-validated to a worst-case static tip of 41.0° (see weight report §4.4). To actually realize those extra prints the collection totes must also rise proportionally — they are sized at ~630L each for the 14-print recovery — so the hard ceiling on a single hauled load is the per-tote 1,000L volume, capping it at ~16 prints.

On-site top-up — extended deployment. A deployment can run past the ~16-print single-load ceiling using the external end-wall bulkhead ports — no cargo-door access required: resupply Blue from a water bowser or tanker through the X1 gravity-fill inlet (tees to both Blue totes), and discharge Brown/Waste through the X3 / X4 drain ports to a holding tank or tanker. In this mode the tote volumes act as buffers, not hard caps, and print count is set by water logistics (bowser visits, disposal access) rather than tote volume. This is a distinct operating mode from the hauled single load: for transport the totes return to their validated fill states (Blue drained, Waste within its return-haul limit). See the Operating Manual for the top-up procedure.

Cooling-water overhead (hot-weather deployments): the evaporative cooler draws clean water from the same Blue circuit (at TAP-01 on the pinhole wall), so it is not free of the processing budget. Its reservoir holds ~4.8 gal (~18 L) and evaporates ~3 L/hour while running (Ventilation Report §5), so a deployment consumes roughly one tankful (~18 L) — about 15% of one print's net Blue draw, or ~1% of the full 1,800 L supply. This is sub-one-print of overhead: it does not move the 14-print count for a 1–2 print outing, but a resupply spent entirely on hot, multi-print sessions should be planned as ~13 effective prints to leave the cooler its margin. The 14-print figure above counts processing water only.

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4. System Architecture

4.1 Blue System — Clean Water Supply

IBC-1 (900L) ──┐
                ├──→ Manifold → BV-01 → P-01 → ACC-01 → BV-05 → Distribution
IBC-2 (900L) ──┘                                                      │
                                                                          ↓
                                                              FLOOD/SPRAY BAR
                                                              ↓ (Processing tray)

• Two IBC totes plumbed in parallel via 1" HDPE manifold with isolation valves
• The two Blue totes are tied at the base by a 1" equalization cross-tie (tank body to tank body, low on the totes) so their levels self-balance as P-01 draws and X1 refills
• P-01: Shurflo 2088 12VDC diaphragm pump — 3.5 GPM, 45 PSI, self-priming
• Check valves: only CV-1 is fitted, on the X1 gravity fill — the single flow path with no pump. Every return and drain leg is pump-driven, and the Shurflo 2088 pumps carry an integral 1-way check valve (2088-554-144 datasheet), so dedicated anti-siphon checks on the IBC-2 return, IBC-3 buffer return and IBC-4 waste legs would be redundant and are not used
• ACC-01: 0.75 L (23.5 oz) pressure accumulator — smooths pump cycling, maintains pressure when pump is off
• Low-level float switch on IBC-2 alerts operator when Blue supply is low
• Spray bar: gantry design — 40×25×3mm 304 SS RHS beam (laid flat, ~15mm pre-camber) spanning the open processing area (3,859mm) between walkway inner edges, with Ø32 wheel carriages rolling on the raised/sloped tray floor beneath walkway grating. A 3/4" LDPE manifold clipped to the beam side feeds 26 side-tapped flat-fan nozzles. See the Processing Tray & Spray Bar report for full mechanical design
• Fill inlet: single external 2" NPT bulkhead fitting (X1) with camlock on the container end wall centerline — gravity feed, no pump required. Inside, an internal tee (near X1) splits to a SIDE entry near the top of BOTH Blue totes (no top-cap access — 52mm headroom), filling them in parallel and gravity-linked — one external hose. Remote resupply from water bowser or tanker (no cargo door access required)

4.2 Brown System — Used Water Recycling

Processing tray sump (P-04 suction pickup)
        │
   P-04 (tray drain transfer pump — suction from sump, lifts ~900mm to IBC-3 side-entry)
        │
     SV-02 SAMPLE TAP (meter incoming used-water pH → set DV-02 routing)
        │
   3W-DV-02 ──────────────────────────────────────────→ (to IBC-4 waste if heavily loaded)
        │
        ↓
   IBC-3 (600L buffer fill, side-entry near top — no top-cap access, 52mm headroom)
        │
       P-02
        │
       F-1 (5-micron MPP sediment)
        │
       F-2 (KDF-55 heavy-metal)
        │
       F-3 (GAC carbon block)
        │
     SV-01 SAMPLE TAP (draw sample → manual meter check before returning)
        │
   3W-DV-01 ──→ pH 6–7, visually acceptable: RETURN TO IBC-2 (Blue)
        │
        └──→ pH drift / discolored: FORWARD TO IBC-4 (waste)

Filter train sizing:

The filter train is three separate 4.5"×20" Big Blue housings (Ø184 × 594mm each; Express Water / Geekpure / iSpring), mounted as a horizontal bank high on the pinhole wall — heads pinned near the ceiling, sumps hanging below. Each has 1" NPT inlet/outlet; a single 1/2"→1" bushing reducer matches P-02's 1/2" output to F-1, and F-1 → F-2 → F-3 connect by short 1" HDPE jumpers with 90° elbows outside the bodies (full mechanical detail in Plumbing Report §3.1).

Stage	Cartridge (4.5"×20")	Removes
F-1	MPP 5-micron melt-blown polypropylene sediment	Gross sediment, fiber lint, Prussian blue particles
F-2	KDF-55 heavy-metal removal	Dissolved iron compounds from ferricyanide wash water
F-3	CTO coconut-shell activated carbon block	Residual organics, color

The 4.5"×20" cartridges carry ~2× the media of a 10", so service intervals run correspondingly longer; the per-stage replacement intervals live in Plumbing Report §3.1. A single 3-stage combo unit (4.5"×20" cartridges, 1" NPT) is an equivalent alternative that eliminates the inter-housing jumpers — any unit accepting standard 4.5"×20" cartridges with 1" NPT ports will work.

pH management: Two pH sample taps are fitted. SV-02 (½" valve + spout on the P-04 tray-drain discharge, before 3W-DV-02) lets the operator meter the incoming used water and choose the DV-02 routing — buffer to IBC-3 or divert straight to IBC-4 waste. SV-01 confirms the cleaned water before it returns: draw the post-filter sample at the SV-01 sample tap (½" valve + spout before 3W-DV-01) and meter it. If filtered water reads pH <6, do nothing — slightly acidic is preferred. If pH >7.5, add citric acid solution (10g citric acid in 1 liter water) via the dosing port in the IBC-3 outlet, stir, retest. Do not return water with pH >8 to the Blue system.

4.3 Black System — Waste Containment

FROM 3W-DV-01 (rejected filter output — pH out of range)
FROM 3W-DV-02 (heavily contaminated drain water — operator judgment)
        │
   IBC-4 (600L waste)
        │
   Sealed, labeled per GHS/OSHA
        │
   TRANSPORT to licensed liquid waste disposal facility

• IBC-4 is a 1,000L caged composite tote with DN50 butterfly valve (S60×6 thread); "600 L"/"1,000 L" are fill levels
• IBC-4 sits in the right end zone in a 2x2 stack: bottom-far position
• Cap sealed before transport; label contents, date, location, UN numbers for ferricyanide/iron compounds
• Drained remotely via external 2" NPT bulkhead fitting with camlock on the container end wall centerline — no need to open cargo doors
• Do not leave IBC valve open — evaporation and UV exposure can drive ferricyanide chemistry

4.4 Processing Tray and Spray Bar

The processing tray and spray bar gantry are fully specified in the Processing Tray & Spray Bar Report. Their role in the water system is summarized here.

Processing tray: A permanently installed 4459 × 2,200mm stainless steel tray sits on the optical zone floor between the film plane rails. A 1:200 dual-axis slope drains wash water to a pressed sump well on the right side nearest the pinhole wall. P-04 draws from the sump via a suction pickup tube — no penetration of the tray floor or container floor.

Drain path: P-04 suction pickup → 1" flexible hose over near rim → P-04 pump on the Corridor Plumbing Panel → 3W-DV-02 diverter → IBC-3 (Brown) or IBC-4 (Waste).

External drain-out risers: The Brown (IBC-3) and Waste (IBC-4) totes are pumped out to the sealed end-wall ports — X3 via P-05, X4 via P-03. The two vertical drain risers run down the IBC corridor gap and are clamped at ~400mm centers to an 18mm marine-ply backing spine that tees perpendicular off the Corridor Plumbing Panel. Its top is capped with a horizontal ply shelf that the Blue fill trunk rests on — so both the drain risers and the fill trunk are supported at the T rather than free-hanging.

Spray bar: A 3,859mm span 304 SS RHS beam gantry (40×25×3mm, laid flat) rolls on the raised/sloped tray floor beneath the walkway grating. Water from P-01 (Blue supply) reaches the bar via BV-05 → 4m flexible hose → ball-joint manifold → 7 feed tubes into the side LDPE manifold → 26 flat-fan nozzles at 150mm centers, spraying down-and-in.

Supply path: P-01 → ACC-01 → rigid 1/2" HDPE pipe along pinhole wall → BV-05 → coiled flexible hose → bulkhead fitting → beam bore → spray holes.

Containment liner: A fresh 6-mil black LDPE sheet is laid over the tray surface before each session to prevent direct stainless-to-print contact and simplify cleanup.

For full construction details, structural analysis, parts list, and engineering drawings, see Processing Tray & Spray Bar.

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5. Plumbing Specification

Pipe sizing

All pump-driven internal runs use 1/2" pipe, matching the Shurflo 2088 pump ports (1/2"-14 male parallel thread). This eliminates trunk-to-manifold reducer fittings entirely. The three Big Blue filter housings have 1" NPT ports: a single 1/2"→1" bushing reducer feeds F-1, the F-1→F-2 and F-2→F-3 jumpers are short 1" HDPE with 90° elbows, and the F-3 outlet connects to DV-01 (1" FNPT). Larger pipe (1" or 2") is used only for the IBC fill/drain lines at the external bulkhead ports and the short filter outlet to DV-01, where gravity flow requires lower restriction. P-03 is mounted separately in the IBC plumbing corridor on the X4 waste drain run.

Internal runs (1/2" HDPE Sch 40):

Circuit	Pipe	Size	Pressure rating	Material
Blue supply (IBC → BV-01 → P-01)	Sch 40 / SDR-11	1/2" nominal (OD 21mm)	100 PSI min	HDPE
Blue discharge (P-01 → ACC-01 → BV-05 → spray bar)	Sch 40 / SDR-11	1/2" nominal (OD 21mm)	100 PSI min	HDPE
Brown suction (IBC-3 → P-02)	Sch 40 / SDR-11	1/2" nominal (OD 21mm)	100 PSI min	HDPE
Brown riser (P-02 → F1 inlet)	Sch 40	1/2" nominal (OD 21mm)	100 PSI min	HDPE
Tray drain suction (sump → P-04)	Reinforced flex hose	1/2" nominal	pump suction	HDPE/PVC braid
DV-02 outputs (→ IBC-3, → IBC-4)	Sch 40	1/2" nominal (OD 21mm)	50 PSI min	HDPE
DV-01 outputs (→ Blue IBC-2, → Black IBC-4)	Sch 40	1/2" nominal (OD 21mm)	50 PSI min	HDPE
ACC-01 inlet/outlet	Sch 40	1/2" nominal (OD 21mm)	125 PSI min	HDPE
Spray bar	SDR-11	3/4" nominal	100 PSI min	HDPE

Filter unit outlet (1" HDPE Sch 40):

Circuit	Pipe	Size	Pressure rating	Material
Filter train (F-3) outlet → SV-01 sample tap → DV-01	Sch 40	1" nominal (OD 33mm)	100 PSI min	HDPE

IBC fill/drain (1" HDPE Sch 40 — gravity flow, not pump-driven):

Circuit	Pipe	Size	Pressure rating	Material
External fill line (X1 bulkhead → tee → both Blue totes)	Sch 40	1" nominal (OD 33mm)	50 PSI min	HDPE
External drain lines (X3/X4 bulkhead → IBCs)	Sch 40	1" nominal (OD 33mm)	50 PSI min	HDPE
X1 fill tee (splits to IBC-1 & IBC-2)	—	1" HDPE equal tee (Banjo TEE100)	50 PSI min	HDPE

At 3.5 GPM, flow velocity in 1/2" pipe (ID ~15.8mm) is approximately 1.1 m/s — well within the recommended 0.5–2.5 m/s range for water systems. The longest internal run (~5.5m from manifold to far-column IBC) contributes less than 0.3 bar friction loss at this velocity.

Why HDPE, not PVC? Standard gray PVC is not rated for photographic chemistry contact and can leach plasticizers. HDPE and CPVC are both acceptable. Do not use copper or galvanized fittings — iron compounds in the wash water will react.

Fittings and connections

Connection type	Use	Standard
2" camlock (type A+B)	IBC tote inlet/outlet	Aluminum or polypropylene
1" NPT threaded	Filter (F-3) outlet → DV-01, inter-housing jumpers, IBC fill/drain lines	HDPE or brass
1/2" NPT threaded	All pump-driven runs, pump ports, manifold connections, ACC-01, ball valves	HDPE or brass
1/2"×1" NPT bushing reducer	P-02 riser to F1 filter inlet (1 required)	Polypropylene or brass
2" NPT bulkhead	External fill/drain port (container wall)	304 SS
Push-fit / compression	Secondary connections	John Guest / Speedfit style

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6. Electrical — 12V DC Power

Item	Current draw	Hours/print	Wh/print
P-01 Blue pump (Shurflo 2088)	7.5 A @ 12V	0.25 hr (15 min run)	22.5 Wh
P-02 Filter-loop feed pump (Shurflo 2088)	7.5 A @ 12V	0.17 hr (10 min run)	15.2 Wh
P-03 Waste pump (Shurflo 2088) — IBC corridor	7.5 A @ 12V	intermittent (waste disposal only)	—
P-04 Tray drain transfer pump (Shurflo 2088)	7.5 A @ 12V	0.08 hr (5 min run)	7.5 Wh
P-05 Brown drain-out pump (Shurflo 2088) — IBC corridor	7.5 A @ 12V	intermittent (drain-out only)	—
pH meter	<0.1 A	—	<1 Wh
Total per print			~46 Wh

A 100 Ah 12V lithium battery (1,200 Wh usable) provides >25 prints of pump power without recharging. A modest 100W solar panel recharges in ~3–4 hours of sun.

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7. Equipment Layout

See Sheet 2 — Plan View (water-system-sheet2.png) for the water-system-specific P&ID layout. All four IBCs are in the provably shadow-free right end zone (X=4,649–5,893mm), arranged in a 2x2 stack. The optical zone contains only the processing tray and perimeter walkways at floor level.

Container floor plan — all systems (top-down, 1:75):

IBCs are arranged in a 2x2 stack in the right end zone, right-justified to the far end wall. Near column: IBC-1 Blue (top) + IBC-3 Brown (bottom). Far column: IBC-2 Blue (top) + IBC-4 Waste (bottom). A 270mm plumbing corridor between the two columns carries all internal supply and return lines. Total physical capacity: 4×1,000L = 4,000L (totes are filled to working levels, not full). All IBCs are loaded empty through the cargo doors and filled/drained remotely via 3x external 2" NPT bulkhead fittings (X1/X3/X4) through the container end wall. IBC wall clearance is 30mm (near wall to near column edge).

Zone	Contents	X (mm)	Yd (mm)	H (mm)
Right end zone	IBC-1 Blue (top, near column)	4,674–5,893	30–1,046	1,168–2,336
Right end zone	IBC-3 Brown (bottom, near column)	4,674–5,893	30–1,046	0–1,010
Right end zone	Plumbing corridor	4,674–5,893	1,046–1,316	0–2,020
Right end zone	IBC-2 Blue (top, far column)	4,674–5,893	1,316–2,332	1,168–2,336
Right end zone	IBC-4 Waste (bottom, far column)	4,674–5,893	1,316–2,332	0–1,010
Pinhole wall face	Pinhole Wall panel — P-02 + 3-stage filter bank (high, sumps hanging)	3,300–3,976	~100	1,746–2,340
IBC plumbing corridor	Corridor panel — P-01/P-03/P-04/P-05 + ACC-01	4,654–5,104	1,046–1,316	355–1,930
Optical zone floor	Processing tray	170–4,629	60–2,300	0–50
Optical zone	No equipment	150–4,649	—	—

All equipment clears the optical cone at every depth — shadow-free proof in Equipment Layout Report.

Hose routing: The corridor pumps (P-01, P-04, P-05, P-03) mount on the Corridor Plumbing Panel at the front of the IBC stack, reaching into the 270mm plumbing corridor between the two IBC columns — so the pump↔tote suction and return lines are short, running entirely within the corridor to the IBCs' corridor-facing DN50 valves. P-02 (Brown filter feed) and the 3-stage filter stack sit on the Pinhole Wall Plumbing Panel on the pinhole wall face. The longest run is the Blue supply to the spray bar: P-01 → ACC-01 → rigid 1/2" HDPE along the pinhole wall to the tray center → BV-05 → ~4m coiled flexible hose → the rolling beam in the optical zone. The tray drain returns the other way — P-04's sump pickup → 1" flexible hose over the near rim → P-04 on the panel → 3W-DV-02 diverter → IBC-3 (Brown) or IBC-4 (Waste). Waste evacuation pumps P-05 (X3 / Brown) and P-03 (X4 / Waste) sit directly on the corridor drain risers, minimizing pipe to the external end-wall ports. The four lines that connect the corridor equipment to the Pinhole Wall panel run together as a flat ribbon in the dead space under the right-walkway grate — see Plumbing Report §8.1 and Walkway Pipe Routing.

External fill/drain ports: Three 2" NPT bulkhead fittings with camlock fittings on the exterior are mounted on the container end wall centerline, stacked vertically:

Port	Function	Connects to
X1 — Fill Blue	Fresh water supply fill	IBC-1 (top, near column) — gravity feed
X3 — Drain Brown	Used water drain	IBC-3 (bottom, near column)
X4 — Drain Waste	Waste water drain	IBC-4 (bottom, far column)

A single external fill port (X1) feeds an internal 1" tee in the corridor, which splits the flow to BOTH Blue IBCs (each branch side-enters the tote's corridor face near the top, 150mm + flange — no top-cap access, only 52mm headroom). The two top totes fill in parallel, so only one external hose is needed — without a separate cross-connect pipe.

This allows remote filling (from water bowser or tanker) and draining (IBC-3/IBC-4 to disposal tanker) without opening the cargo doors or entering the container. Internal plumbing from each port routes through the 270mm central corridor between the two IBC columns to reach the respective tote. All ports are accessible from the container exterior.

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8. Parts List

Item	Spec	Qty	Supplier	Est. cost
IBC tote (1,000 L caged)	Caged composite tote, DN50 butterfly valve (S60×6 thread); side-entry fittings near top	4 ea	Container Exchanger	$320–$600
Bulkhead fitting 2" NPT (304 SS) (4464K115)	External fill/drain port, welded through container wall	3 ea	McMaster-Carr	$75–$120
Shurflo 2088-554-144 pump (P-01 Blue supply)	12VDC, 3.5 GPM, 45 PSI, 1/2" NPSM ports	1 ea	Amazon	$55–$70
Shurflo 2088-554-144 pump (P-02 filter loop)	12VDC, 3.5 GPM, 45 PSI, 1/2" NPSM ports	1 ea	Amazon	$55–$70
Shurflo 2088-554-144 pump (P-03 waste evacuation)	12VDC, 3.5 GPM, 45 PSI; empties IBC-4 residual below X4 (~120L)	1 ea	Amazon	$65
Shurflo 2088-554-144 pump (P-04 tray drain transfer)	12VDC, 3.5 GPM, 45 PSI; tray drain to IBC-3 (~900mm lift)	1 ea	Amazon	$65
Shurflo 2088-554-144 pump (P-05 Brown drain)	12VDC, 3.5 GPM, 45 PSI; evacuates IBC-3 (Brown) residual to the X3 end-wall port	1 ea	Amazon	$65
SeaFlo accumulator (0.75 L) (SFAT-075-125-01)	0.75 L, 125 PSI, 1/2" MNPT	1 ea	Amazon	$35
Shurflo pump mounting bracket	Stainless, 2088 series — one per pump (P-01..P-05)	5 ea	Amazon	$50
Corridor plumbing-panel marine ply (18mm)	4×8 ft 18mm BS 1088 (or equivalent) marine plywood — rear backing board (~170×2196) + drain-riser backing spine (~456×1966) + spacer offcuts; ~1.3 m² used. Price est.	1 sheet	marine plywood supplier / Home Depot	$120–$200
Pump-mount shirt marine ply (25mm)	25mm BS 1088 (or equivalent) marine plywood, ~610×1650 cut piece — pump-mount shirt behind P-01..P-05 + 6× shirt-to-panel spacer blocks. Price est.	1 piece	marine plywood supplier / Home Depot	$70–$130
Corridor panel mount hardware (brackets + fasteners)	6× steel angle brackets (panel → IBC-frame front-portal uprights), shirt-to-panel screws, lag bolts. Price est.	1 lot	Home Depot	$25–$50
Big Blue filter housing 4.5"×20" (separate)	Ø184×594mm/housing (4.5×20), 1" NPT ports — three SEPARATE housings on the slotted-angle skid frame (Pentek / iSpring / Geekpure)	3 ea	Amazon	$114–$186
Slotted steel angle frame 25×25×3mm (filter skid)	~2.5 m 25×25×3mm slotted steel angle + fasteners; bolts to the 18mm ply backing (adjustable housing height)	1 lot	Home Depot	$25–$45
Steel U-bracket (filter housing)	Wraps the housing head; 2 bolts/bracket through the backing board	3 ea	McMaster-Carr	$21–$30
HDPE spacer blocks 25mm (filter skid)	25mm HDPE blocks between U-bracket and backing board — sump-bowl hang clearance	1 lot	McMaster-Carr	$12–$22
1" HDPE inter-housing jumpers	F-01 OUT→F-02 IN, F-02 OUT→F-03 IN — 1" HDPE + 90° elbows routed outside the bodies	1 lot	Ferguson	$18–$32
MPP 5-micron sediment cartridge 4.5"×20"	Melt-blown polypropylene depth filter (F-1 stage); ~50-print interval	2 ea	Amazon	$24–$40
KDF-55 heavy-metal cartridge 4.5"×20"	KDF-55 media for dissolved iron/metal removal (F-2 stage); ~60-print interval	1 ea	Amazon	$40–$70
CTO carbon block cartridge 4.5"×20"	Coconut shell activated carbon block (F-3 stage); ~40-print interval	2 ea	Amazon	$32–$60
Banjo V050FP ball valve 1/2" FNPT	PP full-port quarter-turn; pump-suction isolation BV-01 (P-01), BV-02 (P-05), BV-06 (P-03)	3 ea	Amazon	$18–$30
Banjo V050FP ball valve 1/2" FNPT	PP full-port quarter-turn; pump-suction isolation BV-03 (P-02)	1 ea	Amazon	$6–$10
Banjo V050FP ball valve 1/2" FNPT	PP full-port; supply isolation BV-04 (TAP-01 chem tap), BV-05 (spray-bar feed)	2 ea	Amazon	$12–$20
Banjo V100FP ball valve 1" FNPT	PP full-port; V1/V3/V4, VB1–VB3 (IBC fill/drain)	6 ea	Amazon	$60–$96
3-way diverter valve 1/2" FNPT	L/T-port HDPE-compatible; 3W-DV-02 (tray drain)	1 ea	Amazon	$12–$22
3-way diverter valve 1" FNPT	L/T-port; 3W-DV-01 (filter output)	1 ea	Amazon	$18–$30
pH sample tap (SV-01) — 1/2" PP ball valve + barb spout + branch tee	Filtered-water sample draw before 3W-DV-01; Banjo V050FP 1/2" PP ball valve + downturned 1/2" hose barb on a 1"×1/2" reducing branch tee, panel face above spill line	1 ea	Amazon	$10–$18
pH sample tap (SV-02) — 1/2" PP ball valve + barb spout + branch tee	pH sample on the P-04 tray-drain discharge, before 3W-DV-02; same build as SV-01	1 ea	Amazon	$10–$18
2" polypropylene camlock pairs (M+F)	External bulkhead connections (X1/X3/X4 + spare)	4 pair	Amazon	$20–$32
1/2" NPT 90° elbow polypropylene	All pump-driven run bends	14 ea	Amazon	$28–$56
Banjo EL100-90 elbow 1" NPT	PP 90°; IBC bends, filter outlet to DV-01	4 ea	Amazon	$12–$20
1/2" NPT polypropylene tee	Blue suction/discharge tees, branches	6 ea	Amazon	$12–$24
Banjo TEE100 equal tee 1" NPT	PP; IBC drain tees (the X1 fill is now a 4-way cross)	3 ea	Amazon	$12–$18
1" NPT 4-way cross fitting	X1 fresh-fill 4-way: X1 inlet + IBC-1 + IBC-2 + DV-01 blue recycle return (was a 3-way tee). Cost est.	1 ea	Amazon	$8–$14
1/2" NPT polypropylene union	Maintenance disconnects on pump runs	6 ea	Amazon	$24–$36
1/2"×1" NPT bushing reducer	P-02 riser to F1 filter inlet	1 ea	Amazon	$3–$5
S60×6 to 1" NPT adapter	IBC DN50 valve to 1" HDPE; PP S60×6 male × 1" NPT female	8 ea	Amazon	$64–$120
1" bulkhead tank-body fittings (Blue equalization cross-tie)	Low tank-body penetration in each Blue tote (IBC-1 + IBC-2) for the 1" equalization cross-tie that self-balances the two Blue levels (run made from the 1" HDPE stock). Cost est.	2 ea	Amazon	$12–$24
1" NPT spring check valve (CV1 — X1 gravity fill)	PVC body, EPDM seal, 1" FNPT × FNPT. Only CV-1 (X1 fill) remains — the Shurflo 2088 pumps have integral check valves, so CV-2/CV-3/CV-4 are redundant and dropped	1 ea	Amazon	$8–$14
Steel flat bar 25×3mm — ribbon support cross-brace	Welded between the two right-walkway long bearers at 4 stations to carry the under-walkway pipe ribbon (the four corridor↔pinhole lines); ~300mm each	4 ea	Home Depot	$8–$16
Cushioned pipe clip	Secures the four under-walkway ribbon lines to the support cross-braces (4 lines × 4 supports)	16 ea	Amazon	$16–$32
Thread seal tape (PTFE)	1/2" wide, 260" roll	4 roll	Home Depot	$8
1/2" SDR-11 HDPE pipe	All pump-driven runs (80 ft); matches pump port size	4 stick	Ferguson	$24–$40
1" SDR-11 HDPE pipe	Food-safe blue-stripe 20 ft; filter outlet + IBC lines	1 stick	Ferguson	$12–$18
Banjo TEE100 equal tee, 1" HDPE NPT	X1 fill tee — splits the fill to both Blue totes	1 ea	Amazon	$4–$6
3/4" SDR-11 HDPE pipe	Spray bar run, 20 ft sticks	2 stick	Ferguson	$20–$30
1/2" ID reinforced braided PVC hose	Pump inlet flexible connection, 6 ft per pump	2 length	Amazon	$20
14 AWG duplex marine wire	Tinned copper, 25 ft	1 roll	Amazon	$22
Anderson Powerpole connectors 30A	Pump connections — one pair per pump (P-01..P-05)	5 pair	Amazon	$10
15A blade fuse	Pump Circuit C (single feed, all pumps)	1 ea	Amazon	$5
6-mil black LDPE sheeting	20 ft × 100 ft roll	1 roll	Home Depot	$100
Apera Instruments AI311 PH60 pH meter	Waterproof, 0–16 range, ±0.01 accuracy	1 ea	Amazon	$55
pH calibration solution set	pH 4 + pH 7 buffer sachets	1 set	Amazon	$10
Citric acid, food grade, 5 lb	pH adjustment (acidifier)	2 bag	Amazon	$28
Chemical-resistant labels (GHS)	For IBC totes	1 pack	Amazon	$20
Nitrile gloves, box of 100	Size M/L	2 box	Amazon	$28
Water total				$2,025–$3,060

The processing tray (§6.1), spray bar (§6.2), and IBC stacking frame are itemized in their own reports — Processing Tray & Spray Bar and IBC Stacking — and roll into the Total cost summary below.

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Total cost summary

Category	Low estimate	High estimate
Water equipment — §8 BOM (IBC storage, pumps + accumulator, 3-stage filter train, valves & fittings, pipe, wiring, consumables)	$2,073	$3,123
Processing tray (see Processing Tray report §6.1)	$1,300	$2,015
Spray bar assembly (see Processing Tray report §6.2)	$287	$375
TOTAL	$3,660	$5,513

The Water-equipment row is the generated §8 parts:water BOM total (single source of record for the water subsystem — storage/pumps/filters/valves/pipe/consumables); the tray and spray-bar rows are costing.py blocks. The TOTAL is a hand sum of the three and should itself become a generated block (Phase-1 backlog).

Used IBC totes drive significant savings vs. new. The parts list consolidates to 4 primary suppliers: Amazon (~30 line items — qualifies for bulk/subscribe discounts), McMaster-Carr (tray hardware — single order, fast shipping), Ferguson (HDPE pipe — call for contractor pricing), and Online Metals (SS sheet). Obtain quotes from Ferguson before ordering pipe from Amazon — trade counter pricing is typically 20–30% below retail.

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9. Maintenance

Task	Frequency	Notes
Replace F-1 (5-micron MPP sediment)	~Every 50 prints	Visually inspect — replace sooner if heavily discolored (intervals: plumbing §3.1)
Replace F-2 (KDF-55 heavy-metal)	~Every 60 prints	Replace sooner if flow rate drops
Replace F-3 (GAC carbon block)	~Every 40 prints	Replace if taste/odor test fails
Flush Brown IBC-3	Every 5 prints	Rinse with clean water, inspect for sediment buildup
pH check of filtered output	Every session	Before returning Brown water to Blue system
Drain and rinse Blue IBCs	Annually (or before long storage)	Prevent biofilm formation
Inspect IBC-4 valve and cap	Before every transport	Check for leaks

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10. Safety Notes

1. Ferricyanide in alkaline conditions: Do not allow IBC-4 waste water to contact strong alkalis (sodium hydroxide, bleach). In alkaline + UV conditions, ferricyanide can release trace cyanide ions. Keep pH < 7.5 in all containers. This is a theoretical rather than acute risk at the concentrations involved, but is worth managing.

2. Prussian blue is non-toxic — it is approved as a human antidote medication in some contexts — but the fine particles are a skin/eye irritant. Wear nitrile gloves and eye protection when handling wash trays.

3. Citric acid dosing: Always dissolve before adding to tank. Adding dry acid to iron-rich water can cause a brief exothermic reaction and bubbling. Mix in a separate container first.

4. IBC-4 waste transport: Ensure IBC cap is sealed and ball valve is closed before transport. Label contents before transport. The liquid is not classified as DOT hazardous material at these concentrations, but label clearly and keep upright. Drain remotely via external bulkhead port to a disposal tanker.

5. Electrical: Each pump draws 7.5A at 12V. All five pumps share a single Circuit C (12V, 15A fuse, 14 AWG) and run one at a time, so the single feed carries them — see Plumbing Report §3.2.

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11. Source References

Chemistry and safety: - Photrio — Composition of cyanotype wash water - Ask MetaFilter — Disposing of cyanotyping water - FMCSA ELDT curriculum (HDPE chemical resistance reference)

Suppliers — consolidated by provider (see shopping list for direct part links): - Amazon — Pumps (Shurflo 2088), accumulator, filter housings, cartridges, Banjo valves/fittings, check valves, IBC adapters, electrical, consumables - McMaster-Carr — Bulkhead fittings, tray hardware (bulkhead union, gasket, bolts) - Ferguson Plumbing Supply — HDPE pipe (1" and 3/4" SDR-11) - Container Exchanger — Used IBC totes, California - Online Metals — 304 SS sheet for processing tray - Ronaqua — GAC carbon filter cartridges