§ FG Field Guide 29 topics · evergreen

The data behind
every good day.

Eight environmental variables that explain why fish bit — or didn't. Each guide covers what the number means, how to read it, and what to do with it on the water.

All guides
01
Water Temperature
Optimal ranges, thermocline depth, seasonal patterns, and how bass metabolism shifts with every degree.
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02
Barometric Pressure
Why the 24-hour trend matters more than the absolute reading, and how fronts create the best — and worst — bites of the year.
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03
Water Clarity
The FNU turbidity scale explained. How to match lure color and presentation to clear, stained, and muddy water.
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04
Solunar Theory
Major and minor feeding windows derived from moon position. The science, the debate, and how to use them in practice.
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05
Tide Phase
Rising, falling, high slack, low slack — what each phase does to bait position and how to fish the transitions.
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06
Water Level Trend
Rising water pulls bass shallow into new cover. Falling water concentrates them on main-lake structure. The 3-day trend tells you which world you're fishing.
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07
Wind & Cloud Cover
Wind concentrates bait on windward banks. Overcast skies pull bass shallow. Together they create the best topwater window of the day.
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08
Moon Phase
Full moon, new moon, spawn timing, night feeding patterns. How the 29.5-day lunar cycle shows up in your catch log.
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09
Dissolved Oxygen & The Bite
Understand how dissolved oxygen, not just temperature, dictates bass depth and feeding zones, concentrating them vertically.
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10
Lake Stratification & Turnover
Learn how summer heat stratifies lakes into thermal layers, affecting bass behavior, and how fall turnover re-oxygenates the water column.
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11
Daylight Length & The Bass Calendar
Day length, not just temperature, drives bass's annual calendar. Equinoxes and solstices trigger spawning, feeding, and winter behaviors.
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12
Cold Fronts & Bite Recovery
Post-cold front bass behavior: Understand the science behind pressure changes, feeding shutdowns, and how to fish the bite recovery.
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13
Spawn Temperature Thresholds
Understand how water temperature, from 55°F to 72°F, triggers bass spawn phases and how latitude and depth shift timing.
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14
Forage Cycles & The Shad Year
Explore the annual cycle of threadfin and gizzard shad and its profound influence on bass behavior and location through the seasons.
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15
Aquatic Vegetation Types
Aquatic vegetation types—hydrilla, milfoil, lily pads, eelgrass, coontail, pondweed—dictate bass location, forage, and water quality indicators.
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16
Bottom Composition & Cover
Understand how bottom composition like rock, gravel, sand, clay, and mud impacts bass behavior and location.
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17
Current and Water Flow
Understand how water current dictates bass positioning and behavior. Learn to read flow patterns in rivers and reservoirs, and leverage real-time data for better fishing.
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18
Tributary Inflow & The Mud Line
Rainfall creates tributary inflow. This inflow forms a temperature and turbidity "mud line" where it meets the main lake. This edge concentrates baitfish and offers bass prime ambush points.
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19
Light Penetration & Secchi Depth
Secchi depth defines how deep light penetrates water. This sets the visible hunting range for bass, influencing their behavior and your lure choices.
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20
Wind Direction & The Windward Bank
Wind direction is crucial for bass. Learn why windward banks concentrate plankton and baitfish, creating prime, challenging feeding grounds for bass.
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21
Cloud Cover & Sky Type
Understand how cloud cover and sky type impact bass feeding. Optimize shallow water fishing based on light penetration.
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22
The Shad Spawn Window
Understand the brief, explosive spring shad spawn bite. Learn why water temperature and first light trigger this feeding frenzy and how to find it.
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23
Tannin-Stained Water
Understand how tannins affect water color and light penetration, influencing bass behavior differently than turbidity. Use Bassai data to refine your approach.
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24
Algae Blooms & Water Quality
Understand how algae blooms impact bass fishing by affecting water quality, dissolved oxygen, and pH, and learn to identify pre- and post-bloom feeding windows.
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25
Drought & Falling Water
Understand how extended drought concentrates bass on main-lake structure, exposes new shorelines, and alters spring spawning.
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26
Flood Conditions & High-Water Bass
Learn how rising water levels push bass into new territory and how to fish crawfish patterns effectively during flood conditions.
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27
River vs Reservoir vs Natural Lake
Understand how habitat influences largemouth and smallmouth bass behavior in rivers, reservoirs, and natural lakes. Log your data.
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28
The Sunrise Window
The sunrise window is a crucial summer feeding period. Bass leverage low light, cool water, and exposed baitfish for a highly productive, short-duration bite.
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29
Air Temperature vs Water Temperature
Understand why water temperature, not air temp, dictates bass behavior. Learn about thermal lag and how Bassai data reveals true patterns.
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Also on Bassai
All data fields explained → About Bassai → Support →