Turn decision on scary board

[kom]

I've been flipping back and forth on this one for a few days. I have no idea why I didn't full pot which might have made things a bit easier.

On the turn the pot is $30.75 and effective stacks are 39.

Should I bet the turn and if so how much?

CO is a 54/4/0.37 extremely loose passive calling station, chases weak draws, the usual stuff.

BB is 20/12/1.39. Has seemed reasonable and hasn't been out of line over the 90ish hands at the table.

PokerStars No-Limit Hold'em, $0.50 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

CO ($85.70)
Hero ($48.50)
SB ($51.50)
BB ($49.25)
UTG ($50.50)
MP ($60.60)

Preflop: Hero is Button with Q[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img].
<font color="#CC3333">UTG raises to $2</font>, <font color="#666666">1 fold</font>, CO calls $2, Hero calls $2, <font color="#666666">1 fold</font>, BB calls $1.50.

Flop: ($8.25) Q[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, UTG checks, CO checks, <font color="#CC3333">Hero bets $7.5</font>, BB calls $7.50, UTG folds, CO calls $7.50.

Turn: ($30.75) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, CO checks,Hero....