diff --git a/index/bitmap.go b/index/bitmap.go
index eb0d4db41..5b690243a 100644
--- a/index/bitmap.go
+++ b/index/bitmap.go
@@ -142,11 +142,17 @@ func (s *BlockArray) set_bit(BlockIndex uint8, bit uint8) bool {
 	s.Block[BlockIndex] |= 1 << bit
 	return val == 0
 }
+func (s *BlockArray) clear_bit(BlockIndex uint8, bit uint8) bool {
+	val := s.Block[BlockIndex] & (1 << bit)
+	s.Block[BlockIndex] &= ^(1 << bit)
+	return val != 0
+}
 
 type Chunk struct {
 	Key   uint64
 	Value BlockArray
 }
+
 type Bitmap struct {
 	nodes  *rbtree.Tree
 	bcount uint64
@@ -399,6 +405,7 @@ type IBitmap interface {
 	Get(*Chunk) *Chunk
 	Len() int
 	Inc()
+	Dec()
 	Count() uint64
 	SetCount(uint64)
 	Bits() []uint64
@@ -514,6 +521,11 @@ func (b *Bitmap) Len() int {
 func (b *Bitmap) Inc() {
 	b.bcount += 1
 }
+func (b *Bitmap) Dec() {
+	if b.bcount > 0 {
+		b.bcount -= 1
+	}
+}
 func (b *Bitmap) SetCount(c uint64) {
 	b.bcount = c
 }
@@ -554,6 +566,25 @@ func SetBit(b IBitmap, position uint64) (bool, *Chunk, Address) {
 	}
 	return data_changed, node, address
 }
+
+func ClearBit(b IBitmap, position uint64) (bool, *Chunk, Address) {
+	//Chunk,Chunk_index,bit_offset :=deref(position)
+	address := deref(position)
+
+	item := GetChunk(b, address.ChunkKey)
+	var node *Chunk
+	if item == nil {
+		return false, nil, address
+	} else {
+		node = item
+	}
+	data_changed := node.Value.clear_bit(address.BlockIndex, address.Bit)
+	if data_changed {
+		b.Dec()
+	}
+	return data_changed, node, address
+}
+
 func BitCount(b IBitmap) uint64 {
 	var total uint64
 	total = 0
diff --git a/index/brand.go b/index/brand.go
index 2696b79ee..895ffe887 100644
--- a/index/brand.go
+++ b/index/brand.go
@@ -87,6 +87,15 @@ func (self *Brand) Get(bitmap_id uint64) IBitmap {
 	return b
 }
 
+func (self *Brand) Get_nocache(bitmap_id uint64) (IBitmap, uint64) {
+	bm, ok := self.bitmap_cache[bitmap_id]
+	if ok {
+		return bm.bitmap, bm.category
+	}
+	//I should fetch the category here..need to come up with a good source
+	return self.storage.Fetch(bitmap_id, self.db, self.frame, self.slice)
+}
+
 func (self *Brand) GetFilter(bitmap_id, filter uint64) IBitmap {
 	b, old_filter := self.storage.Fetch(bitmap_id, self.db, self.frame, self.slice)
 	if filter == 0 {
@@ -417,3 +426,35 @@ func (self *Brand) Load(requestChan chan Command, f *Fragment) {
 
 	}
 }
+
+func (self *Brand) ClearBit(bitmap_id uint64, bit_pos uint64) bool {
+	bm1, ok := self.bitmap_cache[bitmap_id]
+	var bm IBitmap
+	filter := uint64(0)
+	if ok {
+		bm = bm1.bitmap
+		filter = bm1.category
+	} else {
+		bm, filter = self.Get_nocache(bitmap_id)
+		if bm.Count() == 0 {
+			return false //nothing to unset
+		}
+	}
+
+	change, chunk, address := ClearBit(bm, bit_pos)
+	if change {
+		val := chunk.Value.Block[address.BlockIndex]
+		/*		self.storage.BeginBatch()
+				self.storage.StoreBlock(bitmap_id, self.db, self.frame, self.slice, filter, address.ChunkKey, int32(address.BlockIndex), val)
+				self.storage.StoreBlock(bitmap_id, self.db, self.frame, self.slice, filter, COUNTERMASK, 0, bm.Count())
+				self.storage.EndBatch()
+		*/
+		if val == 0 {
+			self.storage.RemoveBlock(bitmap_id, self.db, self.frame, self.slice, filter, address.ChunkKey, int32(address.BlockIndex))
+		} else {
+			self.storage.StoreBit(bitmap_id, self.db, self.frame, self.slice, filter, address.ChunkKey, int32(address.BlockIndex), val, bm.Count())
+		}
+		self.rank_count++
+	}
+	return change
+}
diff --git a/index/commands.go b/index/commands.go
index f91cb6a24..24b34809d 100644
--- a/index/commands.go
+++ b/index/commands.go
@@ -348,3 +348,17 @@ func NewTopNAll(n int, categories []uint64) *CmdTopNAll {
 func (self *CmdTopNAll) Execute(f *Fragment) Calculation {
 	return f.TopNAll(self.n, self.categories)
 }
+
+type CmdClearBit struct {
+	*Responder
+	bitmap_id uint64
+	bit_pos   uint64
+}
+
+func NewClearBit(bitmap_id uint64, bit_pos uint64) *CmdClearBit {
+	result := &CmdClearBit{NewResponder("ClearBit"), bitmap_id, bit_pos}
+	return result
+}
+func (self *CmdClearBit) Execute(f *Fragment) Calculation {
+	return f.impl.ClearBit(self.bitmap_id, self.bit_pos)
+}
diff --git a/index/fragment_container.go b/index/fragment_container.go
index 0766703e3..48b7c9741 100644
--- a/index/fragment_container.go
+++ b/index/fragment_container.go
@@ -270,6 +270,18 @@ func (self *FragmentContainer) SetBit(frag_id util.SUUID, bitmap_id uint64, pos
 	return false, errors.New("Invalid Bitmap Handle")
 }
 
+func (self *FragmentContainer) ClearBit(frag_id util.SUUID, bitmap_id uint64, pos uint64) (bool, error) {
+	if fragment, found := self.GetFragment(frag_id); found {
+		request := NewClearBit(bitmap_id, pos)
+		fragment.requestChan <- request
+		result := request.Response()
+		util.SendTimer("fragmant_container_ClearBit", result.exec_time.Nanoseconds())
+		util.SendInc("fragmant_container_ClearBit")
+		return result.answer.(bool), nil
+	}
+	return false, errors.New("Invalid Bitmap Handle")
+}
+
 func (self *FragmentContainer) Clear(frag_id util.SUUID) (bool, error) {
 	if fragment, found := self.GetFragment(frag_id); found {
 		request := NewClear()
@@ -295,6 +307,7 @@ func (self *FragmentContainer) AddFragment(db string, frame string, slice int, i
 type Pilosa interface {
 	Get(id uint64) IBitmap
 	SetBit(id uint64, bit_pos uint64, filter uint64) bool
+	ClearBit(id uint64, bit_pos uint64) bool
 	TopN(b IBitmap, n int, categories []uint64) []Pair
 	TopNAll(n int, categories []uint64) []Pair
 	Clear() bool
diff --git a/index/general.go b/index/general.go
index 3dbf7d727..25041e4b5 100644
--- a/index/general.go
+++ b/index/general.go
@@ -156,3 +156,29 @@ func (self *General) TopNAll(n int, categories []uint64) []Pair {
 	}
 	return results
 }
+
+func (self *General) ClearBit(bitmap_id uint64, bit_pos uint64) bool {
+	bm := self.Get_nocache(bitmap_id)
+	if bm.Count() == 0 {
+		return false
+	}
+	change, chunk, address := ClearBit(bm, bit_pos)
+	if change {
+		val := chunk.Value.Block[address.BlockIndex]
+		if val == 0 {
+			self.storage.RemoveBlock(bitmap_id, self.db, self.frame, self.slice, uint64(0), address.ChunkKey, int32(address.BlockIndex))
+		} else {
+			self.storage.StoreBit(bitmap_id, self.db, self.frame, self.slice, uint64(0), address.ChunkKey, int32(address.BlockIndex), val, bm.Count())
+		}
+	}
+	return change
+}
+
+func (self *General) Get_nocache(bitmap_id uint64) IBitmap {
+	bm, ok := self.bitmap_cache.Get(bitmap_id)
+	if ok && bm != nil {
+		return bm.(*Bitmap)
+	}
+	bm, _ = self.storage.Fetch(bitmap_id, self.db, self.frame, self.slice)
+	return bm.(*Bitmap)
+}
diff --git a/index/storage.go b/index/storage.go
index ad0f67ab2..8be339c9d 100644
--- a/index/storage.go
+++ b/index/storage.go
@@ -4,7 +4,8 @@ type Storage interface {
 	Fetch(bitmap_id uint64, db string, frame string, slice int) (IBitmap, uint64)
 	Store(id uint64, db string, frame string, slice int, filter uint64, bitmap *Bitmap) error
 	StoreBlock(id uint64, db string, frame string, slice int, filter uint64, chunk uint64, block_index int32, block uint64) error
-	StoreBit(bid uint64, db string, frame string, slice int, filter uint64, bchunk uint64, block_index int32, bblock, count uint64)
+	StoreBit(bid uint64, db string, frame string, slice int, filter uint64, chunk uint64, block_index int32, block, count uint64)
+	RemoveBlock(id uint64, db string, frame string, slice int, filter uint64, chunk uint64, block_index int32) error
 	BeginBatch()
 	EndBatch()
 	FlushBatch()
diff --git a/index/storage_cass.go b/index/storage_cass.go
index de198c530..3c8b839ed 100644
--- a/index/storage_cass.go
+++ b/index/storage_cass.go
@@ -17,6 +17,7 @@ type CassandraStorage struct {
 	db                    *gocql.Session
 	batch                 *gocql.Batch
 	stmt                  string
+	dstmt                 string
 	batch_time            time.Time
 	batch_counter         int
 	cass_time_window_secs float64
@@ -55,6 +56,7 @@ func NewCassStorage() Storage {
 
 	obj.db = session
 	obj.stmt = `INSERT INTO bitmap ( bitmap_id, db, frame, slice , filter, ChunkKey, BlockIndex, block) VALUES (?,?,?,?,?,?,?,?)  USING timestamp ?;`
+	obj.dstmt = `DELETE BlockIndex,block FROM bitmap WHERE bitmap_id=? AND db=? AND frame=? AND slice=? AND filter=? AND ChunkKey=? AND BlockIndex=?;`
 	obj.batch = nil
 	obj.batch_time = time.Now()
 	obj.batch_counter = 0
@@ -207,6 +209,10 @@ func (self *CassandraStorage) StoreBit(bid uint64, db string, frame string, slic
 	self.cass_queue.Push(rec)
 }
 
+func (self *CassandraStorage) RemoveBlock(id uint64, db string, frame string, slice int, filter uint64, chunk uint64, block_index int32) error {
+	return nil
+}
+
 type CassQueue struct {
 	size   int64
 	buffer chan CassRecord
diff --git a/index/storage_leveldb.go b/index/storage_leveldb.go
index 1e0077d3e..95980d29f 100644
--- a/index/storage_leveldb.go
+++ b/index/storage_leveldb.go
@@ -170,6 +170,9 @@ func (self *LevelDBStorage) StoreBlock(id uint64, db string, frame string, slice
 	util.SendTimer("leveldb_storage_StoreBlock", delta.Nanoseconds())
 	return nil
 }
+func (self *LevelDBStorage) RemoveBlock(id uint64, db string, frame string, slice int, filter uint64, chunk uint64, block_index int32) error {
+	return nil
+}
 
 func (self *LevelDBStorage) Close() {
 	self.FlushBatch()
diff --git a/index/storage_mem.go b/index/storage_mem.go
index d06d1575d..398c6a146 100644
--- a/index/storage_mem.go
+++ b/index/storage_mem.go
@@ -48,3 +48,6 @@ func (c *MemoryStorage) StoreBlock(bitmap_id uint64, db string, frame string, sl
 }
 func (self *MemoryStorage) StoreBit(bid uint64, db string, frame string, slice int, filter uint64, bchunk uint64, block_index int32, bblock, count uint64) {
 }
+func (self *MemoryStorage) RemoveBlock(id uint64, db string, frame string, slice int, filter uint64, chunk uint64, block_index int32) error {
+	return nil
+}