Help with river value bet size.

[QuietEarner]

Full Tilt Poker - No Limit Hold'em Cash Game - $0.15/$0.30 Blinds - 6 Players - (LegoPoker Hand History Converter)

Hero (SB): $59.10
BB: $25.65
UTG: $51.50
MP: $55.60
CO: $80.80
BTN: $29.30

Reads: <font color="blue">Villain is 34/12/1.2 Plays TPGK hands a little over aggressive, and plays TPWK very passively. He is also a calling station with second pair type hands. Never saw any evidence of him floating flops.

UTG limps very often, not concerned with him preflop.
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Preflop: Hero is dealt Q[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/spade.gif[/img] (6 Players)
UTG calls $0.30, 3 folds, <font color="red">Hero raises to $1.50</font>, BB calls $1.20, UTG calls $1.20

Flop: ($4.50) 6[img]/images/graemlins/diamond.gif[/img] 5[img]/images/graemlins/diamond.gif[/img] Q[img]/images/graemlins/spade.gif[/img] (3 Players)
<font color="red">Hero bets $3.30</font>, BB calls $3.30, UTG folds

Turn: ($11.10) 8[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $7.00</font>, BB calls $7.00

River: ($25.10) 8[img]/images/graemlins/club.gif[/img] (2 Players)

<font color="green">Hero bets ????</font>
<font color="red">Villain has $13.85 left</font>

Is this just an easy put him all in, or is that over doing it.
IF I PUSH: I figure he would fold missed flush, possibly fold a second pair, 75% sure would call with Qx up to T, 95% sure he calls with Qpaint or better.

He calls all of the above for half his remaining, except flush draw.
I'm sure some math problem solves this but I don't know it, and prob couldn't calculate fast enough at the table.