NL5 6-max - bluffing four flush river

Sorry, typo, this is NL10.
These fishes calls always no matter which flush they have. What do you think about my play? How to approach this kind of situations?

iPoker - €0.10 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

Hero (SB): 133.4 BB
BB: 121.6 BB (VPIP: 15.28, PFR: 12.50, 3Bet Preflop: 4.76, Hands: 75)
UTG: 127.6 BB (VPIP: 56.80, PFR: 20.39, 3Bet Preflop: 2.74, Hands: 209)
MP: 96.9 BB (VPIP: 59.09, PFR: 4.55, 3Bet Preflop: 0.00, Hands: 22)
CO: 148.8 BB (VPIP: 15.80, PFR: 9.29, 3Bet Preflop: 2.50, Hands: 546)
BTN: 203.5 BB (VPIP: 33.70, PFR: 20.65, 3Bet Preflop: 14.29, Hands: 94)

Hero posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has Q♣ A♦

UTG raises to 2 BB, MP calls 2 BB, fold, fold, Hero raises to 10 BB, fold, UTG calls 8 BB, fold

Flop: (23 BB, 2 players) 4♠ 3♥ T♠
Hero bets 16.1 BB, UTG calls 16.1 BB

Turn: (55.2 BB, 2 players) 9♠
Hero checks, UTG checks

River: (55.2 BB, 2 players) 2♠
Hero bets 27.6 BB, UTG calls 27.6 BB

Hero mucks Q♣ A♦ (High Card, Ace)
(Pre 45%, Flop 24%, Turn 9%)
UTG shows 6♠ 6♦ (Flush, Ten High)
(Pre 55%, Flop 76%, Turn 91%)
UTG wins 106.8 BB