diff --git a/packages/go-kosu/abci/app.go b/packages/go-kosu/abci/app.go
index f6a01b7d..83c17f01 100644
--- a/packages/go-kosu/abci/app.go
+++ b/packages/go-kosu/abci/app.go
@@ -141,8 +141,6 @@ func (app *App) BeginBlock(req abci.RequestBeginBlock) abci.ResponseBeginBlock {
 			v = app.store.Validator(nodeID)
 		}
 
-		v.Power = vote.Validator.Power
-
 		if vote.SignedLastBlock {
 			v.Active = true
 			v.TotalVotes++
@@ -208,8 +206,12 @@ func (app *App) EndBlock(req abci.RequestEndBlock) abci.ResponseEndBlock {
 			updates = append(updates, update)
 		}
 
-		v.Applied = true
-		app.store.SetValidator(nodeID, v)
+		if v.Power == 0 {
+			app.store.DeleteValidator(nodeID)
+		} else {
+			v.Applied = true
+			app.store.SetValidator(nodeID, v)
+		}
 	})
 
 	return abci.ResponseEndBlock{
diff --git a/packages/go-kosu/abci/cli/cli.go b/packages/go-kosu/abci/cli/cli.go
index 0e8bccda..f7a8f085 100644
--- a/packages/go-kosu/abci/cli/cli.go
+++ b/packages/go-kosu/abci/cli/cli.go
@@ -1,6 +1,8 @@
 package cli
 
 import (
+	"context"
+	"encoding/base64"
 	"fmt"
 	"go-kosu/abci"
 	"go-kosu/abci/types"
@@ -56,7 +58,7 @@ func (cli *CLI) RebalanceTx() *cobra.Command {
 			}
 
 			if res.DeliverTx.IsErr() {
-				printAndExit("deliver tx: %s\n", res.DeliverTx.Log)
+				printAndExit("deliver tx: %s\n", res.DeliverTx.Info)
 			}
 
 			fmt.Printf("ok: < %s>\n", tx.RoundInfo)
@@ -65,6 +67,70 @@ func (cli *CLI) RebalanceTx() *cobra.Command {
 	}
 }
 
+// UpdateValidators updates the validator set by sending a Validator's WitnessTx
+func (cli *CLI) UpdateValidators() *cobra.Command {
+	return &cobra.Command{
+		Use:   "update-validator <block> <pubkey> <address> <power>",
+		Short: "update validators by sending a WitnessTx",
+		Long:  "pubkey needs to be encoded in base64. To remove a validator use power = 0",
+		Args:  cobra.ExactArgs(4),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			block, err := strconv.ParseUint(args[0], 10, 64)
+			if err != nil {
+				return err
+			}
+
+			pubKey, err := base64.StdEncoding.DecodeString(args[1])
+			if err != nil {
+				return err
+			}
+
+			addr, amount := args[2], args[3]
+
+			tx := &types.TransactionWitness{
+				Subject:   types.TransactionWitness_VALIDATOR,
+				Block:     block,
+				PublicKey: pubKey,
+				Address:   addr,
+				Amount:    types.NewBigIntFromString(amount, 10),
+			}
+
+			res, err := cli.client.BroadcastTxCommit(tx)
+			if err != nil {
+				printAndExit("%v\n", err)
+			}
+
+			if res.CheckTx.IsErr() {
+				printAndExit("check tx: %s\n", res.CheckTx.Log)
+			}
+
+			if res.DeliverTx.IsErr() {
+				printAndExit("deliver tx: %s\n", res.DeliverTx.Info)
+			}
+
+			ch, closer, err := cli.client.Subscribe(context.Background(), "tm.event = 'NewBlock'")
+			if err != nil {
+				printAndExit("subscribe: %v", err)
+			}
+			defer closer()
+
+			// wait for the next block
+			<-ch
+
+			set, err := cli.client.Validators(nil)
+			if err != nil {
+				printAndExit("validators: %v", err)
+			}
+
+			fmt.Println("New validator set")
+			for _, v := range set.Validators {
+				fmt.Printf("<%s power:%d>\n", v.PubKey.Address().String(), v.VotingPower)
+			}
+			return nil
+		},
+	}
+}
+
 // QueryRoundInfo queries the round info
 func (cli *CLI) QueryRoundInfo() *cobra.Command {
 	return &cobra.Command{
diff --git a/packages/go-kosu/abci/client.go b/packages/go-kosu/abci/client.go
index 30e32631..7b82f956 100644
--- a/packages/go-kosu/abci/client.go
+++ b/packages/go-kosu/abci/client.go
@@ -96,7 +96,6 @@ func (c *Client) Subscribe(ctx context.Context, q string) (<-chan rpctypes.Resul
 			if err := httpC.Start(); err != nil {
 				return nil, nil, err
 			}
-
 		}
 	}
 
diff --git a/packages/go-kosu/abci/types/types.go b/packages/go-kosu/abci/types/types.go
index cdc0b57f..0f7d0168 100644
--- a/packages/go-kosu/abci/types/types.go
+++ b/packages/go-kosu/abci/types/types.go
@@ -25,6 +25,11 @@ func (b *BigInt) MarshalText() ([]byte, error) {
 	return []byte(str), nil
 }
 
+// Zero returns true if the value is 0
+func (b *BigInt) Zero() bool {
+	return b.BigInt().Cmp(big.NewInt(0)) == 0
+}
+
 var (
 	// ErrNoPubKeyExpected is returned when no public key was expected but it was defined
 	ErrNoPubKeyExpected = errors.New("expected no publicKey for poster witnesses")
diff --git a/packages/go-kosu/abci/witness.go b/packages/go-kosu/abci/witness.go
index a5656aaa..b5d88133 100644
--- a/packages/go-kosu/abci/witness.go
+++ b/packages/go-kosu/abci/witness.go
@@ -9,10 +9,11 @@ import (
 	"go-kosu/store"
 
 	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tendermint/tendermint/crypto/tmhash"
 )
 
 func (app *App) checkWitnessTx(tx *types.TransactionWitness) error {
-	if app.store.LastEvent() >= tx.Block {
+	if app.store.LastEvent() > tx.Block {
 		return errors.New("transaction is older than the recorded state")
 	}
 
@@ -47,8 +48,6 @@ func (app *App) pushTransactionWitness(tx *types.TransactionWitness, nodeID []by
 		})
 	}
 
-	// TODO(gchaincl): delete witness
-
 	wTx := app.store.WitnessTx(tx.Id)
 
 	v := app.store.Validator(nodeID)
@@ -58,38 +57,31 @@ func (app *App) pushTransactionWitness(tx *types.TransactionWitness, nodeID []by
 		return err
 	}
 
-	power := scaleBalance(tx.Amount.BigInt())
-	app.log.Info("adding confirmations", "+power", power, "current", wTx.Confirmations)
-	wTx.Confirmations += uint64(power)
+	app.log.Info("adding confirmations", "+power", v.Power, "current", wTx.Confirmations)
+	wTx.Confirmations += uint64(v.Power)
 	app.store.SetWitnessTx(wTx)
 
-	app.log.Error("info", "threshold", app.confirmationThreshold, "conf", wTx.Confirmations)
+	app.log.Info("info", "threshold", app.confirmationThreshold, "conf", wTx.Confirmations)
 	if app.confirmationThreshold > wTx.Confirmations {
 		return nil
 	}
-
-	if tx.Amount.BigInt().Uint64() == 0 {
-		switch tx.Subject {
-		case types.TransactionWitness_POSTER:
-			app.store.DeletePoster(tx.Address)
-		case types.TransactionWitness_VALIDATOR:
-			app.store.DeleteValidator(nodeID)
-		}
-		return nil
-	}
+	//	app.store.DeleteWitnessTx(tx.Id)
 
 	switch tx.Subject {
 	case types.TransactionWitness_POSTER:
-		app.store.SetPoster(tx.Address, types.Poster{
-			Balance: tx.Amount,
-		})
+		if tx.Amount.Zero() {
+			app.store.DeletePoster(tx.Address)
+		} else {
+			app.store.SetPoster(tx.Address, types.Poster{Balance: tx.Amount})
+		}
 	case types.TransactionWitness_VALIDATOR:
-		app.store.SetValidator(nodeID, &types.Validator{
+		id := tmhash.SumTruncated(tx.PublicKey)
+		app.store.SetValidator(id, &types.Validator{
 			Balance:    tx.Amount,
+			Power:      scaleBalance(tx.Amount.BigInt()),
 			PublicKey:  tx.PublicKey,
 			EthAccount: tx.Address,
-			Active:     false,
-			Power:      power,
+			Applied:    false,
 		})
 	}
 	return nil
diff --git a/packages/go-kosu/cmd/kosu-cli/main.go b/packages/go-kosu/cmd/kosu-cli/main.go
index 2de58c8f..b27635f4 100644
--- a/packages/go-kosu/cmd/kosu-cli/main.go
+++ b/packages/go-kosu/cmd/kosu-cli/main.go
@@ -57,6 +57,7 @@ func main() {
 	}
 	tx.AddCommand(
 		abci.RebalanceTx(),
+		abci.UpdateValidators(),
 	)
 
 	query := &cobra.Command{
diff --git a/packages/go-kosu/store/cosmos/store.go b/packages/go-kosu/store/cosmos/store.go
index 392f0895..c37f6f75 100644
--- a/packages/go-kosu/store/cosmos/store.go
+++ b/packages/go-kosu/store/cosmos/store.go
@@ -164,6 +164,12 @@ func (s *Store) SetWitnessTx(tx store.TransactionWitness) {
 	s.Set("confs:"+string(tx.Id), s.witnessKey, tx.Confirmations)
 }
 
+// DeleteWitnessTx deletes a WitnessTx
+func (s *Store) DeleteWitnessTx(id []byte) {
+	s.Delete("proto:"+string(id), s.witnessKey)
+	s.Delete("confs:"+string(id), s.witnessKey)
+}
+
 // Poster gets a Poster
 func (s *Store) Poster(addr string) *types.Poster {
 	var v types.Poster
diff --git a/packages/go-kosu/store/store.go b/packages/go-kosu/store/store.go
index 9d0fb7be..12ad70b2 100644
--- a/packages/go-kosu/store/store.go
+++ b/packages/go-kosu/store/store.go
@@ -26,6 +26,7 @@ type Store interface {
 	WitnessTxExists([]byte) bool
 	WitnessTx([]byte) TransactionWitness
 	SetWitnessTx(TransactionWitness)
+	DeleteWitnessTx([]byte)
 
 	Poster(string) *types.Poster
 	SetPoster(string, types.Poster)
diff --git a/packages/go-kosu/store/storetest/testing.go b/packages/go-kosu/store/storetest/testing.go
index a9f59e38..1302ac13 100644
--- a/packages/go-kosu/store/storetest/testing.go
+++ b/packages/go-kosu/store/storetest/testing.go
@@ -99,6 +99,7 @@ func TestValidator(t *testing.T, s store.Store) {
 	addr := []byte{0, 1, 2, 3, 4}
 	v := &types.Validator{
 		PublicKey: []byte{0, 1, 2, 3, 4},
+		Power:     10,
 	}
 	s.SetValidator(addr, v)