diff --git a/README.md b/README.md
index f51048da..879d9375 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,7 @@ void setup (){
 
   Kaleidoscope.setup();
 
+  WavepoolEffect.idle_timeout = 5000;  // 5 seconds
   WavepoolEffect.activate();
 }
 ```
@@ -37,6 +38,15 @@ as early as possible, so the plugin can catch all relevant key presses.
 The plugin provides the `WavepoolEffect` object, which has the following
 properties:
 
+### `.idle_timeout`
+
+> When to keys are being pressed, light will periodically splash across
+> the keyboard.  This value sets the delay in ms before that starts.
+>
+> To disable the idle animation entirely, set this to 0.
+>
+> Default is 5000 (5 seconds).
+
 ## Dependencies
 
 * [Kaleidoscope-LEDControl](https://github.com/keyboardio/Kaleidoscope-LEDControl)
diff --git a/src/Kaleidoscope/LED-Wavepool.cpp b/src/Kaleidoscope/LED-Wavepool.cpp
index dea177f4..66b21571 100644
--- a/src/Kaleidoscope/LED-Wavepool.cpp
+++ b/src/Kaleidoscope/LED-Wavepool.cpp
@@ -21,12 +21,13 @@
 
 namespace kaleidoscope {
 
-int8_t WavepoolEffect::map_[2][WP_WID*WP_HGT];
+int8_t WavepoolEffect::surface[2][WP_WID*WP_HGT];
 uint8_t WavepoolEffect::page = 0;
 uint8_t WavepoolEffect::frames_since_event = 0;
+uint16_t WavepoolEffect::idle_timeout = 5000;  // 5 seconds
 /* unused
 // map geometric space (14x5) into native keyboard coordinates (16x4)
-uint8_t WavepoolEffect::positions[WP_HGT*WP_WID] = {
+PROGMEM const uint8_t WavepoolEffect::positions[WP_HGT*WP_WID] = {
      0,  1,  2,  3,  4,  5,  6,    9, 10, 11, 12, 13, 14, 15,
     16, 17, 18, 19, 20, 21, 64,   64, 26, 27, 28, 29, 30, 31,
     32, 33, 34, 35, 36, 37, 22,   25, 42, 43, 44, 45, 46, 47,
@@ -35,7 +36,7 @@ uint8_t WavepoolEffect::positions[WP_HGT*WP_WID] = {
 };
 */
 // map native keyboard coordinates (16x4) into geometric space (14x5)
-uint8_t WavepoolEffect::rc2pos[ROWS*COLS] = {
+PROGMEM const uint8_t WavepoolEffect::rc2pos[ROWS*COLS] = {
      0,  1,  2,  3,  4,  5,  6,    59, 66,    7,  8,  9, 10, 11, 12, 13,
     14, 15, 16, 17, 18, 19, 34,    60, 65,   35, 22, 23, 24, 25, 26, 27,
     28, 29, 30, 31, 32, 33, 48,    61, 64,   49, 36, 37, 38, 39, 40, 41,
@@ -51,7 +52,7 @@ void WavepoolEffect::begin(void) {
 }
 
 void WavepoolEffect::init(void) {
-  memset(map_, 0, sizeof(map_));
+  memset(surface, 0, sizeof(surface));
 }
 
 Key WavepoolEffect::eventHandlerHook(Key mapped_key, byte row, byte col, uint8_t key_state) {
@@ -60,7 +61,7 @@ Key WavepoolEffect::eventHandlerHook(Key mapped_key, byte row, byte col, uint8_t
 
   if (keyIsPressed(key_state)) {
     uint8_t offset = (row*COLS)+col;
-    map_[page][rc2pos[offset]] = 0x7f;
+    surface[page][pgm_read_byte(rc2pos + offset)] = 0x7f;
     frames_since_event = 0;
   }
 
@@ -90,24 +91,26 @@ void WavepoolEffect::update(void) {
   frames_since_event ++;
 
   // needs two pages of height map to do the calculations
-  int8_t *newpg = &map_[page^1][0];
-  int8_t *oldpg = &map_[page][0];
+  int8_t *newpg = &surface[page^1][0];
+  int8_t *oldpg = &surface[page][0];
 
   // rain a bit while idle
-  static uint8_t frames_till_next_drop = 20;
-  if (frames_since_event >= frames_till_next_drop) {
-      frames_till_next_drop = rand() & 0x3f;
-      frames_since_event = 0;
-
-      uint8_t x = rand() % WP_WID;
-      uint8_t y = rand() % WP_HGT;
-      uint8_t rainspot = (y*WP_WID) + x;
-
-      oldpg[rainspot] = 0x7f;
-      if (y > 0) oldpg[rainspot-WP_WID] = 0x50;
-      if (y < (WP_HGT-1)) oldpg[rainspot+WP_WID] = 0x50;
-      if (x > 0) oldpg[rainspot-1] = 0x50;
-      if (x < (WP_WID-1)) oldpg[rainspot+1] = 0x50;
+  static uint8_t frames_till_next_drop = 0;
+  if (idle_timeout > 0) {
+    if (frames_since_event >= (frames_till_next_drop + (idle_timeout >> 6))) {
+        frames_till_next_drop = rand() & 0x3f;
+        frames_since_event = idle_timeout >> 6;
+
+        uint8_t x = rand() % WP_WID;
+        uint8_t y = rand() % WP_HGT;
+        uint8_t rainspot = (y*WP_WID) + x;
+
+        oldpg[rainspot] = 0x7f;
+        if (y > 0) oldpg[rainspot-WP_WID] = 0x50;
+        if (y < (WP_HGT-1)) oldpg[rainspot+WP_WID] = 0x50;
+        if (x > 0) oldpg[rainspot-1] = 0x50;
+        if (x < (WP_WID-1)) oldpg[rainspot+1] = 0x50;
+    }
   }
 
   // calculate water movement
@@ -165,7 +168,7 @@ void WavepoolEffect::update(void) {
   for (byte r = 0; r < ROWS; r++) {
     for (byte c = 0; c < COLS; c++) {
       uint8_t offset = (r*COLS) + c;
-      int8_t value = oldpg[rc2pos[offset]];
+      int8_t value = oldpg[pgm_read_byte(rc2pos+offset)];
 
       cRGB color;
       uint16_t intensity;
diff --git a/src/Kaleidoscope/LED-Wavepool.h b/src/Kaleidoscope/LED-Wavepool.h
index 77a207cc..e00cfa54 100644
--- a/src/Kaleidoscope/LED-Wavepool.h
+++ b/src/Kaleidoscope/LED-Wavepool.h
@@ -21,31 +21,27 @@
 #include <Kaleidoscope.h>
 #include <Kaleidoscope-LEDControl.h>
 
-#define WAVEPOOL(v, ...) ({static kaleidoscope::wavepool::v _effect __VA_ARGS__; &_effect;})
-
 #define WP_WID 14
 #define WP_HGT 5
 
 namespace kaleidoscope {
 class WavepoolEffect : public LEDMode {
  public:
-  class ColorComputer {
-   public:
-    virtual cRGB compute(uint8_t *step) = 0;
-  };
-
   WavepoolEffect(void);
 
   void begin(void) final;
   void init(void) final;
   void update(void) final;
 
+  // ms before idle animation starts after last keypress
+  static uint16_t idle_timeout;
+
  private:
   static uint8_t frames_since_event;
-  static int8_t map_[2][WP_WID*WP_HGT];
+  static int8_t surface[2][WP_WID*WP_HGT];
   static uint8_t page;
-  //static uint8_t positions[WP_HGT*WP_WID];  // unused
-  static uint8_t rc2pos[ROWS*COLS];
+  //static PROGMEM const uint8_t positions[WP_HGT*WP_WID];  // unused
+  static PROGMEM const uint8_t rc2pos[ROWS*COLS];
 
   static Key eventHandlerHook(Key mapped_key, byte row, byte col, uint8_t key_state);
 };