Nut flush on paired river vs Call Station

[TheRempel]

Normally against a standard calltard I fire the river 100% but he was playing incredibly weird. I would not have been surprised to see him overcall with KK after being 'tricky' by checking second last to act after raising preflop. I really felt like he'd probably only call with the king or queen high flush which is probably about half of his flush range since he'll play a lot of really weak combo draws the same way. Just one of those cases where you're basically playing a guy who can barely read his own hand and it becomes more difficult than playing a seasoned player.

I should've just set him in but I checked behind after a few seconds because his weird super-call station style really had me boggled as to what his true range was. He had the second nut flush and I probably could've gotten the rest with a little bit 'time down and bet' play-acting. He didn't lead on the turn because he's not even considering what I have. He just knows he has the second nut flush and I tried to bluff him off the same hand minutes ago.

I'm not sure if there would be any point to betting less than what he has left against this player. It became very apparent later on that he was totally clueless. In about 200 hands he never raised a single street postflop except for the river, and then he went for a checkraise about 90% of the time. The only time he ever bet for value he bet like 1/4 pot. A lot of the time players like this are really just fish in the old school sense, they have no idea how to play poker whatsoever so I wouldn't expect him to understand that he's getting 2:1 on his call on the river, but I would expect him to think that somehow his river checkraise when I bet 175 on the river is the right play cause he has like the eighth nuts, so I feel that any bet less than a shove (unless to induce if I had a better read) is pretty useless.