diff --git a/src/main/java/com/gtnewhorizons/modularui/common/widget/SlotGroup.java b/src/main/java/com/gtnewhorizons/modularui/common/widget/SlotGroup.java
index 8d2af75..aed1d7b 100644
--- a/src/main/java/com/gtnewhorizons/modularui/common/widget/SlotGroup.java
+++ b/src/main/java/com/gtnewhorizons/modularui/common/widget/SlotGroup.java
@@ -5,6 +5,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
@@ -233,7 +234,7 @@ public static class FluidGroupBuilder {
         private Boolean controlsAmount;
         private IDrawable[] background;
         private Function<IFluidTank, IFluidTanksHandler> tankHandlerCreator;
-        private Function<IFluidTanksHandler, FluidSlotWidget> widgetCreator;
+        private BiFunction<Integer, IFluidTanksHandler, FluidSlotWidget> widgetCreator;
 
         private FluidGroupBuilder(List<IFluidTank> fluidTanks, int slotsPerRow) {
             this.fluidTanks = fluidTanks;
@@ -257,7 +258,7 @@ public SlotGroup build() {
                 tankHandlerCreator = tank -> new FluidTanksHandler(new FluidTankLongDelegate(tank));
             }
             if (widgetCreator == null) {
-                widgetCreator = h -> new FluidSlotWidget(h, 0);
+                widgetCreator = (i, h) -> new FluidSlotWidget(h);
             }
 
             SlotGroup slotGroup = new SlotGroup();
@@ -266,7 +267,7 @@ public SlotGroup build() {
             }
             int x = 0, y = 0;
             for (int i = startFromSlot; i < endAtSlot + 1; i++) {
-                FluidSlotWidget toAdd = widgetCreator.apply(tankHandlerCreator.apply(fluidTanks.get(i)));
+                FluidSlotWidget toAdd = widgetCreator.apply(i, tankHandlerCreator.apply(fluidTanks.get(i)));
                 toAdd.setPhantom(phantom);
                 toAdd.setControlsAmount(controlsAmount, false);
                 toAdd.setBackground(background).setPos(new Pos2d(x * 18, y * 18));
@@ -309,7 +310,7 @@ public FluidGroupBuilder tankHandlerCreator(Function<IFluidTank, IFluidTanksHand
             return this;
         }
 
-        public FluidGroupBuilder widgetCreator(Function<IFluidTanksHandler, FluidSlotWidget> widgetCreator) {
+        public FluidGroupBuilder widgetCreator(BiFunction<Integer, IFluidTanksHandler, FluidSlotWidget> widgetCreator) {
             this.widgetCreator = widgetCreator;
             return this;
         }
diff --git a/src/main/java/com/gtnewhorizons/modularui/test/TestTile.java b/src/main/java/com/gtnewhorizons/modularui/test/TestTile.java
index 08d9afb..acd6b28 100644
--- a/src/main/java/com/gtnewhorizons/modularui/test/TestTile.java
+++ b/src/main/java/com/gtnewhorizons/modularui/test/TestTile.java
@@ -276,9 +276,10 @@ private Widget createPage3() {
                                 .setSynced(false, false).setPos(99, 85))
                 .addChild(
                         SlotGroup.ofFluidTanks(Collections.singletonList(fluidTank2), 1).controlsAmount(true)
-                                .phantom(true).widgetCreator(h -> {
+                                .phantom(true).widgetCreator((slotIndex, h) -> {
                                     FluidSlotWidget widget = new FluidSlotWidget(h);
-                                    widget.dynamicTooltip(() -> Collections.singletonList("Dynamic tooltip"));
+                                    widget.dynamicTooltip(
+                                            () -> Collections.singletonList("Dynamic tooltip " + slotIndex));
                                     return widget;
                                 }).build().setPos(38, 47))
                 .addChild(new FluidSlotWidget(fluidTank1).setPos(20, 47))