Possible Independent Variables

  • air movement (wind speeds, wind direction)
  • chemical concentration (low to high concentration)
  • chemicals (none vs. household chemicals)
  • dissolved gases (oxygen, carbon dioxide)
  • environment (simple, complex, large, small, maze, pen)
  • foods (types, enhancers, freshness)
  • light color (red, orange, yellow, green, blue, violet)
  • light intensity (absence or presence; high to low intensity)
  • light quality (incandescent, fluorescent, natural)
  • nutrients (natural vs. synthetic; commercial brand A vs. brand B)
  • salinity (fresh vs. saline, low to high, sodium chloride vs. other salts)
  • sound (volume, pitch, rhythm, music)
  • temperature treatments (cold to hot, pattern of exposure)
  • water pH (acidic, basic, neutral, pH 0-14)
  • water source (tap, distilled, bottled, stream, lake, ocean)