NL10 K9o vs fisy player on BU isolated the limper

This hand is actually the bottom of my BTNvUTG isoraise range. So I might iso here too. I think your sizing could be only 4bb because you are in position, but that's a small thing.
You are playing against a fish who will call with a lot of hands, he has weaker pockets, 7x, weaker 9x, some overcards, draws... I think when you hit, it is ok to just bet. Same goes for turn, draws don't complete and I think it is reasonable to bet and get value from his pocket 55 or flush draw.
I would only bet a bit smaller. Because we are little unsure whether we are ahead or not but we still want to get value from passive calling machine I would use something like 40% sizing.

No need for that large bets.

Both blinds seem active and I may skip iso raising here.

Yes, probably not iso-ing here is best. This holdings do not flop strong draws, strong pairs and have nut potential. So it is better to just skip.

I disagree with betting small. I think betting big fits the villain more, cause the villain will call with a lot of worse hands. The T on the turn is a good card for me so I fire again, river would be check back even if I improve to bottom full house.

It ended well. This time. Don't get me wrong now, but say we build a big pot with a trash hand, hit second pair, keep betting big, lose the pot, who's really the fish? It will take many small successes (which is what you can hope for) to compensate. Small hand - small pot. Especially versus fish (or we are the fish).

Well,really ended it well, it might be that I have been exploited here.... Yes, I won the pot. But I might not have been ahead of 50% of the calling range of villain?

Well yes we have 2nd pair, I know that.

Preflop was not good to start with. It really is the biggest mistake in the hand and making a big pot oop without card advantage. Probably check back turn is better. But I think if I bet I want to bet big with big part of my range. This hand is not the best hand to keep betting with.

Thanks for the advice!

U really put the hammer down on this one. Big bets all the way.
If I m multitabling, I m just passing this hand, but no problem by playing it.
Would bet a bit lower to induce more calls from worse.
Edit: and yeah, pot control also.