$100r basic spot with set

[djk123]

villain is mossified84. he seems to like to flat call me. given he just flatted flop, i doubt he has a set or overpair. board seems too drawy to give a free card on turn, right? what do you think is the optimal bet size? Oh I have 7690 left on turn.

Poker Stars
No Limit Holdem Tournament
Blinds: t150/t300
(Ante: t25)
9 players
Converter

Stack sizes:
UTG: t10339
UTG+1: t22455
MP1: t5240
MP2: t14217
MP3: t8722
djk123: t10415
Button: t19208
SB: t1554
BB: t7487

Pre-flop: (9 players) djk123 is CO with T[img]/images/graemlins/heart.gif[/img] T[img]/images/graemlins/diamond.gif[/img]
5 folds, <font color="#cc0000">djk123 raises to t900</font>, Button calls t900 <font color="aaaaaa">(pot was t1575)</font>, SB folds, BB calls t600 <font color="aaaaaa">(pot was t2475)</font>.

Flop: 6[img]/images/graemlins/club.gif[/img] T[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] (t3075, 3 players)
BB checks, <font color="#cc0000">djk123 bets t1800</font>, Button calls t1800 <font color="aaaaaa">(pot was t4875)</font>, BB folds.

Turn: 2[img]/images/graemlins/heart.gif[/img] (t6675, 2 players)