25NL - Hero makes nut straight on turn - Flushy board - bet size?

[automaton_22]

I just screwed this hand up big time, by under-betting the turn. Let's just say I had the nuts on the turn and ended up doubling Villain up on the river.

How much to we turn bet here, and why?
Discuss.

[Yeah I called under the gun with KQs. This will be sacreligious to some of you, and is not my usual play. It was my last hand and I just wanted a cheap flop, the table was pretty passive. I got the cheap flop. Lets not focus on this in this thread].

Party Poker
No Limit Holdem Ring game
Blinds: $0.10/$0.25
6 players
Converter

Stack sizes:
Hero: $35.29
UTG+1: $23.72
CO: $18.58
Button: $25.69
SB: $30.55
BB: $24.75

Pre-flop: (6 players) Hero is UTG with K[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/spade.gif[/img]
Hero calls, UTG+1 folds, CO calls, 2 folds, 2 folds, BB checks.

Flop: Q[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/heart.gif[/img] ($0.85, 3 players)
BB checks, Hero checks, <font color="#cc0000">CO bets $1</font>, BB folds, Hero calls.

Turn: T[img]/images/graemlins/club.gif[/img] ($2.85, 2 players)
<font color="#cc0000">Hero bets ?