diff --git a/app/Livewire/Forms/Studio/Master/FormulaForm.php b/app/Livewire/Forms/Studio/Master/FormulaForm.php
index 1366160..9de6464 100644
--- a/app/Livewire/Forms/Studio/Master/FormulaForm.php
+++ b/app/Livewire/Forms/Studio/Master/FormulaForm.php
@@ -22,7 +22,7 @@ public function rules(): array
         return [
             'quality' => ['required', 'string', 'max:20'],
             'size' => ['required', 'integer', 'min:1'],
-            'volume' => ['required', new UnsignedInteger],
+            'volume' => ['required', new UnsignedInteger, 'lte:size'],
         ];
     }
 
diff --git a/app/Livewire/Studio/Master/Formula.php b/app/Livewire/Studio/Master/Formula.php
index e490557..eb241fa 100644
--- a/app/Livewire/Studio/Master/Formula.php
+++ b/app/Livewire/Studio/Master/Formula.php
@@ -13,6 +13,7 @@
 use App\Traits\WithUpdatedData;
 use Flux\Flux;
 use Illuminate\Contracts\View\View;
+use Illuminate\Support\Collection;
 use Livewire\Attributes\On;
 use Livewire\Attributes\Title;
 use Livewire\Component;
@@ -24,7 +25,7 @@ class Formula extends Component
 
     public FormulaForm $form;
 
-    public array $formulas = [];
+    public Collection $formulas;
 
     public string $method = 'create';
 
@@ -49,8 +50,7 @@ public function mount(): void
                     ->sortBy('volume')
                     ->values()
                     ->all()
-            )
-            ->all();
+            );
 
         $this->sizes = Bottle::distinct()->orderBy('size')->pluck('size')->toArray();
     }
@@ -67,22 +67,24 @@ public function create(): void
 
         $formula = $this->form->store();
 
-        // push new formula to collection
         $size = $formula->size;
+
         $newFormula = [
             'hash' => $formula->hash,
             'quality' => $formula->quality,
             'volume' => $formula->volume,
         ];
 
-        if (! isset($this->formulas[$size])) {
-            $this->formulas[$size] = [];
-        }
+        // Get the group for this size, or an empty Collection
+        $group = $this->formulas->get($size, collect());
 
-        $this->formulas[$size][] = $newFormula;
+        // Add, then re-sort
+        $group = $group->push($newFormula)
+            ->sortBy('volume')
+            ->values();
 
-        // Sort by volume
-        usort($this->formulas[$size], fn ($a, $b) => $a['volume'] <=> $b['volume']);
+        // Put it back
+        $this->formulas->put($size, $group);
 
         $this->toast('Rumus berhasil ditambahkan.');
 
@@ -107,18 +109,19 @@ public function update(): void
         $formula = $this->form->update();
 
         // update array formulas
-        foreach ($this->formulas as &$group) {
-            foreach ($group as &$item) {
-                if ($item['hash'] === $formula->hash) {
-                    $item['quality'] = $formula->quality;
-                    $item['volume'] = $formula->volume;
-                    // Hash doesn't change
-                }
-            }
-            // re-sort
-            usort($group, fn ($a, $b) => $a['volume'] <=> $b['volume']);
-        }
-        unset($group, $item); // Break references
+        $this->formulas = $this->formulas->map(function ($group) use ($formula) {
+            return collect($group)
+                ->map(function ($item) use ($formula) {
+                    if ($item['hash'] === $formula->hash) {
+                        $item['quality'] = $formula->quality;
+                        $item['volume'] = $formula->volume;
+                    }
+
+                    return $item;
+                })
+                ->sortBy('volume')
+                ->values();
+        });
 
         $this->toast('Rumus berhasil diperbarui.');
 
@@ -134,11 +137,16 @@ public function delete(FormulaModel $formula): void
         // update array formulas
         $size = $formula->size;
 
-        if (isset($this->formulas[$size])) {
-            $this->formulas[$size] = array_values(array_filter($this->formulas[$size], fn ($item) => $item['hash'] !== $formula->hash));
+        if ($this->formulas->has($size)) {
+            $group = collect($this->formulas->get($size))
+                ->reject(fn ($item) => $item['hash'] === $formula->hash)
+                ->values()
+                ->all();
 
-            if (empty($this->formulas[$size])) {
-                unset($this->formulas[$size]);
+            if (empty($group)) {
+                $this->formulas->forget($size);
+            } else {
+                $this->formulas->put($size, $group);
             }
         }