Darkroom Sustainability Cheat Sheet
The Hierarchy (in order of impact)
| Priority | Concern | Action |
|---|---|---|
| 1 | Silver in fixer | Recover it. Always. |
| 2 | Water in washing | Use HCA + sequential changes |
| 3 | Fixer efficiency | Two-bath system, test don't guess |
| 4 | Hazardous chemistry | Proper disposal |
| 5 | Developer choice | Matters least—choose for results |
Silver Recovery Reminder
Your fixer contains 3,000–8,000 mg/L silver. Aquatic life dies at 0.6 μg/L.
☐ Collect ALL spent fixer ☐ Process with steel wool OR collect for hazardous waste ☐ Never pour fixer down the drain
Two-Bath Fixing
[FIRST BATH - older] ←── prints/film enter here (brief fix)
↓ does heavy lifting, accumulates silver
[SECOND BATH - fresher] ←── ensures complete fixing (full time)
↓
When first bath exhausted:
1. Discard first bath (after silver recovery)
2. Promote second → first
3. Make fresh second bath
Capacity: 4–10× single-bath fixing
Ilford Wash Method (Film)
| Step | Fill tank | Inversions | Drain |
|---|---|---|---|
| 1 | Fresh water | 5 | Completely |
| 2 | Fresh water | 10 | Completely |
| 3 | Fresh water | 20 | Completely |
| 4 | Wetting agent rinse | — | Done |
Total water: ~2 litres per roll
Print Washing (Fibre Paper)
- Rinse — 2 tray changes or 2 min running water
- HCA bath — 10 minutes with agitation
- Final wash — 3 sequential tray fills, 2 min each
Total water: ~10–15 litres per session (vs. 100+ traditional)
Quick Disposal Reference
| ✓ Drain-safe | ⚠ Neutralise first | ✗ Hazardous waste |
|---|---|---|
| Oxidised B&W developer | Acetic acid stop bath | Fixer (silver) |
| Water from washing | Bleach-fix (silver) | |
| Selenium toner | ||
| Mordançage bleach | ||
| Chromo chemistry |
The 80% Rule
Silver recovery addresses ~80% of your darkroom's environmental impact.
Everything else—developer choice, “natural” chemistry, packaging—is marginal by comparison.
Do the big thing first. Then worry about the rest.
Sustainable Darkroom series