Increased Base Fog

• Light leaks in darkroom.
• Safelight lens is cracked or otherwise degraded from age or heat.
• Safelight has a bulb in it that is too large (wattage too high).
• Safelight is improper type for film.
• Developer temperature is too high.
• Developer has been contaminated by fixer.
• No starter was added to fresh developer in the processor.
• Fixer level in the processor is low.
• Developer replenishment rate is too high.
• Processor's rollers are dirty or worn.
• Improper film storage.