diff --git a/src/main/java/com/raoulvdberge/refinedstorage/container/BaseContainer.java b/src/main/java/com/raoulvdberge/refinedstorage/container/BaseContainer.java
index 4000414ef..4b08a53a4 100644
--- a/src/main/java/com/raoulvdberge/refinedstorage/container/BaseContainer.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/container/BaseContainer.java
@@ -187,7 +187,7 @@ public abstract class BaseContainer extends Container {
                 FluidStack actual = slot.getFluidInventory().getFluid(slot.getSlotIndex());
 
                 if (!API.instance().getComparer().isEqual(cached, actual, IComparer.COMPARE_QUANTITY | IComparer.COMPARE_NBT)) {
-                    this.fluids.set(i, actual);
+                    this.fluids.set(i, actual.copy());
 
                     RS.NETWORK_HANDLER.sendTo((ServerPlayerEntity) getPlayer(), new FluidFilterSlotUpdateMessage(slot.slotNumber, actual));
                 }
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/network/SetFilterSlotMessage.java b/src/main/java/com/raoulvdberge/refinedstorage/network/SetFilterSlotMessage.java
index 6da112f30..fba6cd406 100644
--- a/src/main/java/com/raoulvdberge/refinedstorage/network/SetFilterSlotMessage.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/network/SetFilterSlotMessage.java
@@ -1,5 +1,6 @@
 package com.raoulvdberge.refinedstorage.network;
 
+import com.raoulvdberge.refinedstorage.apiimpl.API;
 import com.raoulvdberge.refinedstorage.container.slot.filter.FilterSlot;
 import com.raoulvdberge.refinedstorage.container.slot.legacy.LegacyFilterSlot;
 import net.minecraft.entity.player.PlayerEntity;
@@ -42,7 +43,12 @@ public class SetFilterSlotMessage {
                             Slot slot = container.getSlot(message.containerSlot);
 
                             if (slot instanceof FilterSlot || slot instanceof LegacyFilterSlot) {
-                                slot.putStack(message.stack);
+                                // Avoid resetting allowed tag list in the pattern grid.
+                                if (API.instance().getComparer().isEqualNoQuantity(slot.getStack(), message.stack)) {
+                                    slot.getStack().setCount(message.stack.getCount());
+                                } else {
+                                    slot.putStack(message.stack);
+                                }
                             }
                         }
                     }
diff --git a/src/main/java/com/raoulvdberge/refinedstorage/network/SetFluidFilterSlotMessage.java b/src/main/java/com/raoulvdberge/refinedstorage/network/SetFluidFilterSlotMessage.java
index 462ed230a..89d6a77dd 100644
--- a/src/main/java/com/raoulvdberge/refinedstorage/network/SetFluidFilterSlotMessage.java
+++ b/src/main/java/com/raoulvdberge/refinedstorage/network/SetFluidFilterSlotMessage.java
@@ -1,5 +1,7 @@
 package com.raoulvdberge.refinedstorage.network;
 
+import com.raoulvdberge.refinedstorage.api.util.IComparer;
+import com.raoulvdberge.refinedstorage.apiimpl.API;
 import com.raoulvdberge.refinedstorage.container.slot.filter.FluidFilterSlot;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.inventory.container.Container;
@@ -40,7 +42,14 @@ public class SetFluidFilterSlotMessage {
                         Slot slot = container.getSlot(message.containerSlot);
 
                         if (slot instanceof FluidFilterSlot) {
-                            ((FluidFilterSlot) slot).getFluidInventory().setFluid(slot.getSlotIndex(), message.stack);
+                            FluidFilterSlot fluidFilterSlot = (FluidFilterSlot) slot;
+
+                            // Avoid resetting allowed tag list in the pattern grid.
+                            if (API.instance().getComparer().isEqual(fluidFilterSlot.getFluidInventory().getFluid(slot.getSlotIndex()), message.stack, IComparer.COMPARE_NBT)) {
+                                fluidFilterSlot.getFluidInventory().getFluid(slot.getSlotIndex()).setAmount(message.stack.getAmount());
+                            } else {
+                                fluidFilterSlot.getFluidInventory().setFluid(slot.getSlotIndex(), message.stack);
+                            }
                         }
                     }
                 }