diff --git a/src/grid.rs b/src/grid.rs
index c32b91c..5544eef 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -11,7 +11,6 @@ pub struct PopulationConfig {
     pub sensor_angle: f32,
     pub rotation_angle: f32,
 
-    decay_factor: f32,
     deposition_amount: f32,
 }
 
@@ -27,7 +26,6 @@ impl PopulationConfig {
         PopulationConfig {
             sensor_distance: rng.gen_range(0.0..=64.0),
             step_distance: rng.gen_range(0.2..=2.0),
-            decay_factor: rng.gen_range(0.1..=0.1),
             sensor_angle: rng.gen_range(0.0_f32..=120.0).to_radians(),
             rotation_angle: rng.gen_range(0.0_f32..=120.0).to_radians(),
             deposition_amount: rng.gen_range(5.0..=5.0),
@@ -92,7 +90,7 @@ impl Grid {
             self.width,
             self.height,
             radius as f32,
-            self.config.decay_factor,
+            0.1, // decay is always 0.1
         );
     }