diff --git a/nanovna.h b/nanovna.h
index 552fcb1..b416499 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -285,10 +285,13 @@ extern void tlv320aic3204_select(int channel);
 #ifdef __SCROLL__
 extern  uint16_t _grid_y;
 #define GRIDY  _grid_y
-#define HEIGHT_SCROLL     180
-#define HEIGHT_NOSCROLL   230
+extern uint16_t graph_bottom;
+#define BIG_WATERFALL   90
+#define SMALL_WATERFALL 180
+#define NO_WATERFALL    CHART_BOTTOM
+#define CHART_BOTTOM   230
 #define SCROLL_GRIDY      (HEIGHT_SCROLL / NGRIDY)
-#define NOSCROLL_GRIDY    (HEIGHT_NOSCROLL / NGRIDY)
+#define NOSCROLL_GRIDY    (CHART_BOTTOM / NGRIDY)
 #else
 #define GRIDY             (230 / NGRIDY)
 #endif
diff --git a/plot.c b/plot.c
index 0fd01d2..3012a6f 100644
--- a/plot.c
+++ b/plot.c
@@ -29,7 +29,8 @@
 
 
 #ifdef __SCROLL__
-uint16_t _grid_y = NOSCROLL_GRIDY;
+uint16_t _grid_y = (CHART_BOTTOM / NGRIDY);
+uint16_t graph_bottom = CHART_BOTTOM;
 static int waterfall = false;
 #endif
 static void cell_draw_marker_info(int x0, int y0);
@@ -2316,7 +2317,7 @@ static void update_waterfall(void){
   // Waterfall only in 290 or 145 points
   if (!(sweep_points == 290 || sweep_points == 145))
     return;
-  for (i = HEIGHT_NOSCROLL-1; i >=HEIGHT_SCROLL+2; i--) {		// Scroll down
+  for (i = CHART_BOTTOM-1; i >=graph_bottom+1; i--) {		// Scroll down
     ili9341_read_memory(OFFSETX, i  , w_width, 1, w_width*1, spi_buffer);
            ili9341_bulk(OFFSETX, i+1, w_width, 1);
   }
@@ -2324,12 +2325,12 @@ static void update_waterfall(void){
   for (i=0; i< w_width; i++) {			// Add new topline
     uint16_t color;
 #ifdef _USE_WATERFALL_PALETTE
-    uint16_t y = _PALETTE_ALIGN(CELL_Y(index[i])); // should be always in range 0 - HEIGHT_SCROLL
+    uint16_t y = _PALETTE_ALIGN(CELL_Y(index[i])); // should be always in range 0 - graph_bottom
 //    y = (uint8_t)i;  // for test
     color = waterfall_palette[y];
 #elif 0
-    uint16_t y = CELL_Y(index[i]); // should be always in range 0 - HEIGHT_SCROLL
-    uint16_t ratio = (HEIGHT_SCROLL - y)*2;
+    uint16_t y = CELL_Y(index[i]); // should be always in range 0 - graph_bottom
+    uint16_t ratio = (graph_bottom - y)*2;
 //    ratio = (i*2);    // Uncomment for testing the waterfall colors
     int16_t b = 255 - ratio;
     if (b > 255) b = 255;
@@ -2344,7 +2345,7 @@ static void update_waterfall(void){
     gamma_correct(b);
     color = RGB565(r, g, b);
 #else
-    uint16_t y = CELL_Y(index[i]); // should be always in range 0 - HEIGHT_SCROLL
+    uint16_t y = CELL_Y(index[i])* (graph_bottom == BIG_WATERFALL ? 2 : 1); // should be always in range 0 - graph_bottom *2 depends on height of scroll
     // Calculate gradient palette for range 0 .. 192
     // idx     r   g   b
     //   0 - 127   0   0
@@ -2371,30 +2372,34 @@ static void update_waterfall(void){
       spi_buffer[2*i+1] = color;
     }
   }
-  ili9341_bulk(OFFSETX, HEIGHT_SCROLL+2, w_width, 1);
+  ili9341_bulk(OFFSETX, graph_bottom+1, w_width, 1);
 }
 
 int get_waterfall(void)
 {
   return(waterfall);
 }
+enum {W_OFF, W_SMALL, W_BIG};
 
 void
 toggle_waterfall(void)
 {
-  if (!waterfall) {
-    _grid_y = SCROLL_GRIDY;
-    ili9341_fill(OFFSETX, HEIGHT_SCROLL, LCD_WIDTH - OFFSETX, HEIGHT_NOSCROLL - HEIGHT_SCROLL, 0);
-    waterfall = true;
+  if (waterfall == W_OFF) {
     w_min = (int)min_level;
     w_max = (int)peakLevel;
     if (w_max < w_min + 20)
       w_max = w_min + 20;
-
+    graph_bottom = SMALL_WATERFALL;
+    waterfall = W_SMALL;
+  } else if (waterfall == W_SMALL) {
+    graph_bottom = BIG_WATERFALL;
+    waterfall = W_BIG;
   } else {
-    _grid_y = NOSCROLL_GRIDY;
-    waterfall = false;
+    graph_bottom = NO_WATERFALL;
+    waterfall = W_OFF;
   }
+  _grid_y = graph_bottom / NGRIDY;
+  ili9341_fill(OFFSETX, graph_bottom, LCD_WIDTH - OFFSETX, CHART_BOTTOM - graph_bottom, 0);
   request_to_redraw_grid();
 }
 void
diff --git a/sa_core.c b/sa_core.c
index 87c8378..0a437ba 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -1913,7 +1913,7 @@ sweep_again:                                // stay in sweep loop when output mo
       scandirty = false;
     if (break_on_operation && operation_requested) {                        // break loop if needed
       if (setting.actual_sweep_time_us > ONE_SECOND_TIME && MODE_INPUT(setting.mode)) {
-        ili9341_fill(OFFSETX, HEIGHT_NOSCROLL+1, WIDTH, 1, 0);              // Erase progress bar
+        ili9341_fill(OFFSETX, CHART_BOTTOM+1, WIDTH, 1, 0);              // Erase progress bar
       }
       return false;
     }
@@ -1953,8 +1953,8 @@ sweep_again:                                // stay in sweep loop when output mo
 
       if (setting.actual_sweep_time_us > ONE_SECOND_TIME && (i & 0x07) == 0) {  // if required
     	int pos = i * (WIDTH+1) / sweep_points;
-        ili9341_fill(OFFSETX, HEIGHT_NOSCROLL+1, pos, 1, BRIGHT_COLOR_GREEN);     // update sweep progress bar
-        ili9341_fill(OFFSETX+pos, HEIGHT_NOSCROLL+1, WIDTH-pos, 1, 0);
+        ili9341_fill(OFFSETX, CHART_BOTTOM+1, pos, 1, BRIGHT_COLOR_GREEN);     // update sweep progress bar
+        ili9341_fill(OFFSETX+pos, CHART_BOTTOM+1, WIDTH-pos, 1, 0);
       }
 
       // ------------------------ do all RSSI calculations from CALC menu -------------------
@@ -2409,7 +2409,7 @@ sweep_again:                                // stay in sweep loop when output mo
 
   //    redraw_marker(peak_marker, FALSE);
   //  STOP_PROFILE;
-  ili9341_fill(OFFSETX, HEIGHT_NOSCROLL+1, WIDTH, 1, 0);
+  ili9341_fill(OFFSETX, CHART_BOTTOM+1, WIDTH, 1, 0);
 
   palSetPad(GPIOB, GPIOB_LED);
   return true;
@@ -2604,7 +2604,7 @@ void draw_cal_status(void)
     rounding  = true;
   const char * const unit = unit_string[setting.unit];
 
-  ili9341_fill(0, 0, OFFSETX, HEIGHT_NOSCROLL, 0x0000);
+  ili9341_fill(0, 0, OFFSETX, CHART_BOTTOM, 0x0000);
   if (MODE_OUTPUT(setting.mode)) {     // No cal status during output
     return;
   }