I have to agree with Jed here. We have one that wasn't done right and it leaks. Nothing like worrying every year here in the desert that your fishes are at risk.
I haven't stayed current, but you need to make sure your dozer man does it right also. Something about now they scrape from more than one direction and it seals off the bottom of the pond.
I'd be careful with any chemical sealers.
To keep it simple, around here Largemouths and Green Sunfish are a good combination.
