Chemical Problems Troubleshooting

Film photography chemistry seems simple—developer, stop, fix, wash—but each solution is a carefully balanced system. When chemistry goes wrong, the effects appear on your film.

This guide covers common chemical problems, how to identify them, and how to prevent them.

What to Buy First

For B&W development, start with:

• Developer: Ilford ID-11 or Kodak D-76 (powder, economical) or Ilford Ilfotec DD-X (liquid, convenient)
• Stop bath: Ilford Ilfostop or plain water
• Fixer: Ilford Rapid Fixer or Kodak Fixer

This setup costs approximately £20-30 and will process 15-20 rolls.

Developer Problems

Developer is the most critical and most temperamental chemistry. It determines your image.

Oxidation

What it is: Developer oxidises when exposed to air. The active developing agents (metol, hydroquinone, phenidone, etc.) react with oxygen and lose potency.

Signs of oxidation:

Effects on film:

• Reduced activity (underdevelopment)
• Longer development times needed
• Eventually no useful development at all
• Inconsistent results as oxidation progresses

Prevention:

• Use fresh developer
• Store in full, sealed bottles (minimise air headspace)
• Use accordion-style bottles or marbles to displace air
• Mix only what you'll use soon
• Some developers (Rodinal) resist oxidation better than others

Contamination

Fixer in developer: Even small amounts of fixer contaminating developer cause problems:

• Immediately stops development
• Silver dissolved before it forms the image
• Results in thin, blank, or mottled negatives

Stop bath in developer:

• Neutralises the developer
• Development stops prematurely

Other contamination:

• Oils from skin
• Soap residue
• Tap water impurities

Prevention:

• Use separate, labelled containers for each chemical
• Pour carefully—no splashing
• Clean equipment between sessions
• Use dedicated graduates for each solution

Dilution Errors

Too concentrated:

• Faster development than expected
• Higher contrast
• Possible fogging

Too dilute:

• Slower development than expected
• Lower contrast
• May not fully develop film before oxidation exhausts the developer

Common dilution mistakes:

• Confusing stock vs working dilution
• Misremembering ratios (1+1 vs 1:1)
• Wrong measurement units
• Not accounting for previous dilution

Understanding dilution notation:

• 1+1 means 1 part stock + 1 part water (two parts total)
• 1:1 means the same thing
• 1+4 means 1 part stock + 4 parts water (five parts total)
• Some use 1:4 to mean the same as 1+4; others use it differently—check your source

Temperature Effects

Development too cold:

• Significantly reduced activity
• Longer times needed than charts indicate
• May not fully develop before exhaustion

Development too warm:

• Increased activity
• Shorter effective time
• Possible fog
• Risk of reticulation with temperature shock

Standard temperatures:

• B&W: 20°C (68°F) standard, 18-24°C workable with adjustment
• C-41: 38°C (100.4°F) ±0.5°C
• E-6: 38°C (100.4°F) ±0.3°C

Stop Bath Problems

Stop bath is the simplest chemistry but still matters.

Indicator Stop Baths

Most stop baths contain indicator dye that changes colour when exhausted.

How they work:

• Fresh: typically yellow or orange
• Exhausted: purple or dark
• Colour change indicates pH is no longer acidic enough

Common brand indicators:

• Kodak Indicator Stop Bath: yellow → purple
• Ilford Ilfostop: yellow → purple
• Sprint Stop Bath: yellow → blue

When indicator changes colour: Replace immediately. Continued use won't stop development effectively.

Contamination Issues

Developer in stop bath:

• Neutralises acid faster
• Reduces capacity
• May cause streaking if significant

Fixer in stop bath:

• Less critical
• Stop bath still functions
• May reduce capacity slightly

Why Stop Bath Matters

For prints:

• Stops development instantly
• Prevents developer from contaminating fixer
• Extends fixer life significantly

For film: Some argue stop bath is optional for film—a water rinse works. However:

• Acid stop bath halts development instantly (water is slower)
• Extends fixer life
• More important in rotary processing where carryover is minimal

Stop bath alternatives:

• Water rinse: works but slower, uses more fixer capacity
• Plain water with 30 seconds agitation: acceptable for most B&W film
• Always use acid stop for prints

Fixer Problems

Fixer (hypo) removes unexposed silver halide, making the image permanent. Fixer problems cause visible issues.

Exhaustion

The most common fixer problem. Fixer capacity is limited.

What happens when fixer exhausts:

• Fixing takes longer (and longer, and longer)
• Eventually, film doesn't clear completely
• Milky or cloudy appearance remains
• Unfixed silver halide darkens over time (staining)
• Image fades years later

Testing fixer exhaustion:

Rule of thumb: Fix for twice the clearing time. If clearing takes 2 minutes, fix for 4 minutes. If clearing time has tripled from fresh, replace fixer.

Silver Buildup

Used fixer accumulates dissolved silver.

Problems:

• Reduces fixing efficiency
• Eventually reaches capacity
• Silver can deposit back onto film (silvering out)

Solution:

• Track fixer usage
• Replace before capacity is reached
• Silver-recovery systems available for high-volume users (also environmentally preferable)

Incomplete Fixing

Symptoms:

• Milky or cloudy areas on film
• Film looks "foggy" even in unexposed areas
• Print tones shift toward pink/magenta over time
• Gradual fading of image

Causes:

• Exhausted fixer
• Insufficient fixing time
• Film not properly agitated in fixer
• Fixer too cold (slows fixing)

Testing:

• Residual fixer test solutions (Kodak HT-2 or similar)
• Drop on processed film; no colour change = properly fixed
• Yellow/brown stain = residual fixer present

Two-Bath Fixing

For archival processing, use two fixer baths.

How it works:

Why it matters: The first bath does most of the work but becomes contaminated with silver. The second bath ensures complete fixing with relatively fresh fixer. This maximises archival permanence.

Hardening vs Non-Hardening Fixers

Hardening fixers:

• Contain alum or similar hardening agent
• Toughens the emulsion
• Useful for warm-temperature processing
• Can make negatives harder to retouch
• May interfere with some toners

Non-hardening fixers:

• Modern emulsions don't usually need hardening
• Better for toning (emulsion more receptive)
• Preferred for fiber prints
• Standard for most contemporary work

Washing Problems

Washing removes all the chemistry—especially fixer. Inadequate washing causes long-term damage.

Residual Fixer

Fixer left in the emulsion causes:

• Yellowing and staining over time
• Image fading
• Print deterioration

For archival work:

• Test for residual fixer (HT-2 test or similar)
• Extend washing if any residual detected
• Use hypo clearing agent to reduce wash times

Washing Aids (Hypo Clearing Agents)

What they do: Convert fixer compounds into forms that wash out faster in water. Dramatically reduces wash time, especially for fiber paper.

Common products:

• Kodak Hypo Clearing Agent
• Ilford Washaid
• Heico Perma Wash

Typical use:

• 1-2 minutes in hypo clear after fixing
• Reduces fiber paper wash from 60+ minutes to 10-20 minutes
• Not strictly necessary for RC paper (which washes quickly anyway)

Washing Requirements by Material

Water temperature:

• Warmer water washes more effectively
• 20-25°C (68-77°F) for B&W
• Keep wash water similar temperature to processing to avoid reticulation

Water flow:

• Adequate flow matters more than time
• Stagnant water reaches equilibrium and stops washing
• Cascading or running water continuously dilutes fixer

Storage Issues

Shelf Life Expectations

Developer concentrates:

Fixer:

• Unmixed: very long shelf life
• Mixed working solution: months if stored properly
• Used: weeks to months depending on silver load

Stop bath:

• Very stable (it's mostly water and acid)
• Years if sealed

Proper Storage Containers

Good containers:

• Glass bottles (best)
• HDPE plastic bottles (good)
• Accordion-style bottles (eliminate air)
• Dark or opaque (protects from light)

Bad containers:

• Metal (corrosion)
• Thin plastic that collapses and then rebounds (pumps in air)
• Clear containers in sunlight
• Partially full containers with lots of air

Temperature Effects on Storage

Too cold:

• Some chemicals may crystallise
• Generally fine for concentrates
• Don't freeze liquid developers

Too hot:

• Accelerates oxidation
• Reduces shelf life dramatically
• Colour chemistry especially sensitive

Ideal storage:

• Room temperature (18-24°C) or cooler
• Consistent temperature (no cycling)
• Dark location

Mixing Errors

Order of Mixing

Many developers must be mixed in specific order.

Typical order:

1. Water at correct temperature
2. Each component in specified sequence
3. More water to final volume
4. Stir between additions

Why order matters: Some chemicals won't dissolve properly if added to cold water or in the wrong order. Some react with each other if combined directly.

Example—D-76: Add metol first (dissolves in cool water), then hydroquinone (needs sulfite present), etc. Wrong order can cause incomplete mixing or precipitation.

Temperature for Dissolving

Most powdered developers dissolve better in warm water.

General guidance:

• Start with water at 40-50°C (104-122°F)
• Add chemicals with stirring
• Allow to cool to working temperature before use
• Some chemicals (sodium thiosulfate in fixer) cool the solution significantly as they dissolve

Common Calculation Mistakes

Dilution confusion:

• Forgetting whether dilution already applied
• Mixing up 1+1 with 1:2
• Using wrong total volume

Unit confusion:

• Millilitres vs fluid ounces
• Grams vs ounces
• Temperature °C vs °F

Volume errors:

• Not accounting for liquid displacement
• Not filling to final mark after additions

Prevention:

• Use a consistent system
• Write out calculations before mixing
• Double-check units
• Use marked graduates

Equipment Hygiene

Cross-Contamination Between Chemicals

The most critical hygiene issue. Even tiny amounts of fixer in developer ruins the developer.

Prevention:

• Dedicated containers for each chemical (label clearly)
• Rinse graduates between solutions
• Never share containers without thorough cleaning
• Consider colour-coded containers (red for stop, blue for fixer, etc.)

Tank and Reel Cleaning

After each session:

• Rinse thoroughly with water
• Allow to dry completely before next use
• Check reel spirals for crud buildup

Periodic deep cleaning:

• Soak in weak acid solution (vinegar or dilute stop bath)
• Scrub with soft brush
• Rinse thoroughly
• Dry completely

Signs of dirty equipment:

• White deposits (fixer residue)
• Staining
• Film sticking on reels
• Uneven development patterns

Tray Hygiene (Printing)

Print trays accumulate chemistry residue.

Good practices:

• Rinse trays after each session
• Periodic deep cleaning with tray cleaner
• Inspect for cracks (harbors bacteria and chemicals)
• Replace stained or damaged trays

Disposal

Environmental Considerations

Developer:

• Generally biodegradable
• Dilute and dispose down drain in most areas
• Check local regulations

Stop bath:

• Dilute acid
• Neutralise with baking soda if required locally
• Then dispose down drain

Fixer:

• Contains dissolved silver (environmental concern and potential value)
• Should not go directly down drain in quantity
• Silver recovery recommended

Bleach/blix (colour processing):

• More hazardous than B&W chemicals
• Check local regulations
• May require hazardous waste disposal

Silver Recovery

Why recover silver:

• Environmental responsibility
• Economic value (silver prices fluctuate but it's always worth something)
• Often required by regulations for high-volume users

Methods:

• Steel wool precipitation (simple, cheap)
• Electrolytic recovery (more complete)
• Send to silver recovery service

For home users:

• Collect used fixer in a dedicated container
• When you have enough, use steel wool method or take to photo shop/service

Local Regulations

Regulations vary significantly by location:

• Some areas allow dilute drain disposal
• Others require professional disposal
• High-volume users often face stricter rules
• Check with your local water authority

Summary

• Developer is fragile—protect from air, contamination, and age
• Stop bath is simple—watch the indicator, replace when exhausted
• Fixer capacity is limited—test regularly, use two-bath for archival work
• Washing matters—use washing aids for fiber paper, test residual if uncertain
• Storage extends life—full containers, cool, dark
• Mix carefully—right order, right temperature, right calculations
• Keep equipment clean—contamination causes subtle, persistent problems
• Dispose responsibly—especially fixer with its silver content

Most chemical problems are preventable through good habits: fresh chemistry, proper storage, clean equipment, and consistent procedures. When problems do occur, understanding the chemistry helps you diagnose the cause and avoid repeating it.