Full stacks.

1. UTG limps (21/13), and I raise [5h] to $5 on the button. Blinds folds and UTG calls.

2. Flop [Qh][4s], pot $11. UTG checks, I bet $9, UTG calls.

3. Turn , pot $29. UTG checks, I bet $21.

4. River , pot $70. UTG checks and I check behind.

I was betting the turn both for value from a flush draw and to try to push him off a weak ace or queen. The only set he can show up here with is 44 and I think it's unlikely after he c/c flop.

Is the second barrel good? Should we fire a third?

I don't try to push people off a pair of aces. We know he probably shouldn't call the river with almost 100% of his range but many players will call there with a weak ace.

Personally I don't like the second barrel much here, but its not terrible. I wouldn't fire a third since you can win a showdown against any flush draw that doesn't contain an 8, and he should have folded a Q on the turn. That leaves sets (unlikely) and top pair hands left in his range and I just don't see how you are going to be successfull trying to push a NL100 player off top pair.

I used to agree with that line of thinking triple B (and I guess I still do), but I'm just not really stacking AT/AJ with AQ here so wondering if I should take a more aggressive approach when I don't have it it in these spots.

+ I'm running bad so I'm trying to fix leaks.

People don't fold aces.