The choice is all in and take the hand as he folds his flush draw. If he is a tight player he shouldn't call you or call and wait for the river and have to make a big decision if the flush comes.
If it's amicro stake tournement I'm all in and take the chips already in the pot if I can. I hate to slow play these as you leave yourself open to a suck out.
In a higher stack one I would possibly just raise a further 300 and if he calls watch for the flush on the river.
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