PushPull Tank

PushPull Tank Lab is an offline-first process workbench for home darkroom photographers, photo-club students, community-college analog courses, and street shooters who develop B&W and C-41 film themselves. The core loop is a live tank workbench—not a shoot journal. Pick a film stock and desired push/pull stops, lock tank volume and reel count, then generate chemistry dilutions, target temperatures, and a timed step sequence with on-screen agitation cadence you follow while standing at the tank. FILM STOCK LIBRARY Seed entries for common stocks such as HP5+, Tri-X, T-Max, Portra, and Superia. Each stock includes base ISO, process family (B&W, C-41, E-6), and recommended agitation style. PUSH/PULL STOPS Select stops to recalculate development time multipliers and flag temperature sensitivity bands so times stay consistent with your chemistry and room conditions. TANK WORKBENCH Enter tank model capacity, reel count, and film format. The app computes working-solution volume and concentrate amounts from stock dilution ratios—accurate mixes without spreadsheets. CHEMISTRY RECIPE CARDS Developer, stop, fixer, and stabilizer cards with mix-from-concentrate and mix-from-stock modes, stored locally on device. PROCESS RUNNER Step list, visible countdown, and agitation pattern cues (invert, twist, rest) that stay inside the app UI while you work at the tank. CUSTOM HOUSE RECIPES Save your own processes with notes on water quality, pre-wash, and hypo-clear steps for repeatable club or personal standards. TEMPERATURE HELPER °C/°F toggle plus quick offsets for cold-room versus warm-room starting chemistry. BOTTLE INVENTORY Local list of concentrates and working solutions with remaining-volume fields and reorder hints—no account or cloud required. SHAREABLE PROCESS CARDS Export plain-text process cards via the Android share sheet for club handouts or personal archives. First-run onboarding covers safe handling basics, ventilation reminders, and how push/pull stops map to time. All core tools work offline so home developers can mix accurate dilutions and run consistent process steps without guesswork.