200NL, common situation

I don't have reads here but how tight do my opponents have to be for me to fire here? Also, what's your usual bet size for this sort of bet if you do decide to go for it?

PokerMind $200 NL Hold 'em
10max table, 9 handed
Hand created by PokerMind SuperConverter
View Hand in PokerMind

Stacks:
Hero (Button): $200
SB: $200
BB: $200
UTG: $200
UTG+1: $200
MP: $200
MP+1: $200
HJ: $200
CO: $200

PREFLOP: Hero is Button with Thttp://www.pokerenlightenment.com/mo...mondsmilie.png Khttp://www.pokerenlightenment.com/mo...padesmilie.png
6 folds, Hero raises to $7, SB calls $6, BB calls $5

FLOP: 7http://www.pokerenlightenment.com/mo...eartsmilie.png Ahttp://www.pokerenlightenment.com/mo...padesmilie.png 8http://www.pokerenlightenment.com/mo...padesmilie.png (3 players, $21 total pot)
SB checks, BB checks

No more than $15 is fine

Board is wet enough that I would bet closer to full pot.