diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/storage/ItemMonitorBlockEntity.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/storage/ItemMonitorBlockEntity.kt
index 76d18a1a8..cbb109b60 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/storage/ItemMonitorBlockEntity.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/storage/ItemMonitorBlockEntity.kt
@@ -43,9 +43,10 @@ import ru.dbotthepony.mc.otm.registry.MBlockEntities
 import ru.dbotthepony.mc.otm.set
 import ru.dbotthepony.mc.otm.storage.*
 import java.math.BigInteger
-import java.util.IdentityHashMap
-import java.util.UUID
+import java.util.*
 import java.util.function.Supplier
+import kotlin.collections.HashMap
+import kotlin.collections.HashSet
 
 class ItemMonitorPlayerSettings : INBTSerializable<CompoundTag> {
 	enum class RefillSource(val component: TranslatableComponent) {
@@ -163,13 +164,11 @@ private fun takeOne(inventory: Inventory, item: ItemStack): Boolean {
 	return false
 }
 
-private fun takeOne(set: Set<UUID>, view: IStorageProvider<ItemStackWrapper>): Boolean {
-	for (id in set) {
-		val extracted = view.extractStack(id, BigInteger.ONE, false)
+private fun takeOne(id: UUID?, view: IStorageProvider<ItemStackWrapper>): Boolean {
+	val extracted = view.extractStack(id ?: return false, BigInteger.ONE, false)
 
-		if (!extracted.isEmpty) {
-			return true
-		}
+	if (!extracted.isEmpty) {
+		return true
 	}
 
 	return false
@@ -230,9 +229,7 @@ class ItemMonitorBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) :
 		val craftingRecipe = craftingRecipe
 
 		if (oldRecipe != craftingRecipe) {
-			for (i in craftingGridTuples.indices) {
-				craftingGridTuples[i] = HashSet()
-			}
+			Arrays.fill(craftingGridTuples, null)
 
 			val poweredView = poweredView
 
@@ -241,14 +238,14 @@ class ItemMonitorBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) :
 					val item = craftingGrid[i]
 
 					if (!item.isEmpty) {
-						poweredView[ItemStackWrapper(item).key()]?.let(craftingGridTuples[i]::add)
+						craftingGridTuples[i] = poweredView[ItemStackWrapper(item).key()]
 					}
 				}
 			}
 		}
 	}
 
-	private val craftingGridTuples = Array(3 * 3) { HashSet<UUID>() }
+	private val craftingGridTuples = arrayOfNulls<UUID>(3 * 3)
 
 	private val craftingMenu = object : AbstractContainerMenu(null, Int.MIN_VALUE) {
 		override fun stillValid(p_38874_: Player): Boolean {
@@ -262,7 +259,7 @@ class ItemMonitorBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) :
 		get() = ITEM_STORAGE
 
 	override fun addStack(stack: ItemStackWrapper, id: UUID, provider: IStorageProvider<ItemStackWrapper>) {
-		// TODO("Not yet implemented")
+		// no op
 	}
 
 	override fun changeStack(stack: ItemStackWrapper, id: UUID, oldCount: BigInteger) {
@@ -270,7 +267,11 @@ class ItemMonitorBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) :
 	}
 
 	override fun removeStack(stack: ItemStackWrapper, id: UUID) {
-		// TODO("Not yet implemented")
+		for (i in craftingGridTuples.indices) {
+			if (craftingGridTuples[i] == id) {
+				craftingGridTuples[i] = null
+			}
+		}
 	}
 
 	init {