diff --git a/scripts/run_simulation.jl b/scripts/run_simulation.jl
index e5955a9..8bd6c69 100644
--- a/scripts/run_simulation.jl
+++ b/scripts/run_simulation.jl
@@ -9,7 +9,7 @@ dx = 1.0
 Du, Dv = Observable(0.16), Observable(0.08)
 F, k = Observable(0.060), Observable(0.062)
 dt = 1.0
-params_obs = Observable(GSParams(N, dx, 0.16, 0.08, 0.08, 0.06))
+params_obs = Observable(GSParams(N, dx, Du[], Dv[], F[], k[]))
 
 function update_params!(params_obs, u, v, feed, kill)
     old = params_obs[]
@@ -39,16 +39,19 @@ function laplacian5(f)
     return (left .+ right .+ down .+ up .- 4 .* center) ./ h2
 end
 
-function step!(U, V)
+function step!(U, V, params_obs::Observable)
     lap_u = laplacian5(U)
     lap_v = laplacian5(V)
-
+    diff_u = params_obs[].Du
+    diff_v = params_obs[].Dv
+    feed_u = params_obs[].F
+    kill_v = params_obs[].k
     u = U[2:end-1, 2:end-1]
     v = V[2:end-1, 2:end-1]
 
     uvv = u .* v .* v
-    u_new = u .+ (Du[] .* lap_u .- uvv .+ F[] .* (1 .- u))
-    v_new = v .+ (Dv[] .* lap_v .+ uvv .- (F[] .+ k[]) .* v)
+    u_new = u .+ (diff_u .* lap_u .- uvv .+ feed_u .* (1 .- u))
+    v_new = v .+ (diff_v .* lap_v .+ uvv .- (feed_u .+ kill_v) .* v)
 
     # Update with new values
     U[2:end-1, 2:end-1] .= u_new
@@ -70,7 +73,7 @@ function step!(U, V)
 end
 function multi_step!(state, n_steps)
     for _ in 1:n_steps
-        heat_obs[] = step!(state[1], state[2])
+        heat_obs[] = step!(state[1], state[2], params_obs)
     end
 end