Good watch, might watch again, and can recommend if you like horror / sharks.
I imagine for someone who doesn't care about sharks, this might actually be a little boring. They're used really well for a horror mechanic, there is almost a Rob Zombie vibe to this one.
The weirdest part of "sharks in a lake" is how the sharks are surviving, or if we believe the movie discussion that it's a "salt water lake". There are lakes of weirder stuff, so a lake of salt water is reasonable, but it is very clear when you are in salt water versus fresh water.
It is honestly the biggest problem with the movie: the rest makes a lot of sense so it doesn't play with your suspension of disbelief. The story is well structured, and the actors mostly do a good job.
Overall, it's just not the best movie though. I personally don't mind forces of nature as adversity / antagonists, I liked "Crawl", but it has to done with a good delivery.
I don't feel like I care about the characters or the sharks all that much.
It feels like there should be options to just stay out of the water, which is what makes "sharks in the ocean" scary, its harder to get away.
In the end its a good watch that feels like it should be a great watch, but that could just be critical thinking defeating my movie experience.